Harmony Relax Firm Mattress King

The Harmony Relax Firm Mattress King is Harmony Products Inc.'s 10 inch three-layer foam mattress in the one-surface king width. It measures 77 inches wide by 79.5 inches long by 10 inches thick, it is made in Canada, and Harmony sells it separately from any base. No Harmony adjustable bed Westin sells ships a king width, so Westin Healthcare sells this mattress on its own, and delivers across Brampton and the Greater Toronto Area.

The Firm feel is the steadier surface of the two Relax builds. The mattress is rated at 350 lbs, the top layer carries Harmony's cooling GelFlex foam, and the base layer is cut to flex with the adjustable base.

Who this mattress is for

King is the one-surface width for two sleepers: 77 inches of uninterrupted mattress with no split down the middle. It needs a bedroom with residential king clearance, and a king-sized frame underneath it. This is the one Relax size sold without a matching Harmony bed underneath it.

None of the Harmony adjustable beds Westin sells ships a king width, so this mattress is a catalog product on its own: it belongs on a king bed frame you already have. Two sleepers who want independent head and foot settings on a Harmony base use the Split King instead, which is two Twin XL mattresses, not one king mattress.

The trade between the two is the trade every king buyer faces. A one-piece king is one seamless surface with no gap down the middle, one set of king sheets, and the lower price of a single mattress; on an adjustable base it flexes as one, so both sleepers share a single head and foot setting. A split king gives each sleeper independent adjustment and its own mattress feel, at the cost of a seam between the two halves and two Twin XL fitted sheets.

Construction and how it works

Harmony builds the Relax in three layers, 10 inches in total:

• Top layer: 2 inches of GelFlex foam, a gel-infused visco-elastic memory foam that carries heat away from the body so the sleeper does not overheat
• Middle layer: 2 inches of firmer memory foam with a quick rebound, so the sleeper does not fight the foam when turning over
• Base layer: a 6 inch firm foam core engineered to flex with the adjustable base

The base layer carries cut outs at the flex points, so the foam does not bunch up when the head and foot sections of the Harmony base raise and lower. Harmony's own material describes this articulation design as unique to the Relax line: the mattress is built to move with the base rather than fight it.

The Firm and Plush versions share this build. Firm is the steadier surface feel; Plush softens the feel of the top of the mattress. The rated capacity, the 10 inch thickness, and the 10 year limited warranty are the same for both.

Harmony Relax Firm Mattress King specifications

These are the manufacturer's figures for this mattress. The specification tab holds the stored values.

• Size: King
• Dimensions: 77" x 79.5" x 10"
• Weight capacity: 350 lbs
• Construction: three-layer foam, 2" GelFlex over 2" firmer memory foam over a 6" firm core
• Feel: Firm
• Made in: Canada
• Warranty: 10 year limited

Size and fit

This is the one Relax size that does not line up with a Bed Width setting on a Westin bed: no Harmony adjustable base sold here ships a king width, and the Split King setting is two Twin XL decks, not one 77 inch deck. The mattress is cut 77 inches wide by 79.5 inches long, slightly wider than a residential 76 by 80 Eastern King, so measure the frame before ordering. King flat sheets are the easy bedding match; fitted king sheets vary by brand, so check the fitted width before buying.

If the frame underneath is an adjustable base, know what a one-piece king does there: the whole surface flexes as one, so both sleepers share a single head and foot setting. Foam bends willingly on a base, and the Relax is all foam; what it cannot do is give two people two positions, which is the split king's job. Split-top kings, which split only the head section, exist elsewhere in the industry; Harmony does not build one.

Funding help for a therapeutic mattress in Ontario

Several Ontario funding routes can help with the cost of a therapeutic support surface, and eligibility depends on the person's situation and assessment. Westin Healthcare's staff work with funding programs every week and can point you to the right route for your case. Visit our funding page or call (905) 451-7743 to talk it through before you buy.

Delivery and setup in Brampton and the GTA

Westin's own team delivers across Brampton and the Greater Toronto Area, and this mattress normally travels with the Harmony bed it is paired with: we bring both in, set the bed up, and place the mattress before we leave.

We have three stores in the Brampton and Toronto area if you would rather see one first. For a scheduled in-home delivery, call (905) 451-7743 and we will book the next date that works. Same-day delivery is offered through our hospital bed rental service; purchased mattresses are delivered on a scheduled date.

Mattresses are oversized. The Canada-wide free ground-shipping offer on smaller goods does not apply. If the mattress is going outside the GTA, ask us for a freight quote. Inside Toronto and the GTA, White-Glove Delivery (bring-in, unwrap, test, take packaging away) is described on the shipping policy. Any charge is confirmed on your order.

Which Westin beds this mattress fits

No Westin bed page carries this mattress as a bundle option: the Harmony Hi-Low bed tops out at Split King, which is two Twin XL mattresses rather than one king, and the Harmony 3 bed, the Harmony Pro bed, and the Harmony Lite bed sell Twin XL and Queen widths only. For a Harmony base, pick the Split King setting and two Twin XL mattresses instead. On its own, this mattress belongs on a standard king bed frame. It is not a 36 inch hospital mattress: the hospital-style Harmony 8199 is a different footprint, so check the deck width before ordering.

Service and warranty

The Harmony Relax carries a 10 year limited manufacturer warranty for the original purchaser. When something needs attention you call the shop that sold it: Westin Healthcare has a service and repairs department, and our technicians come to the home.

Frequently asked questions

Will this mattress fit the Harmony Hi-Low bed?

No, and that is deliberate. The widest Harmony Hi-Low setting is Split King, which is two Twin XL decks carrying two Twin XL mattresses. A one-piece 77 inch king mattress has no matching deck, so Westin sells it on its own for a king bed frame rather than as a bed option.

What does the King measure?

The 2026 Harmony price list prints the King at 77 inches wide by 79.5 inches long by 10 inches thick. Harmony's earlier sell sheet printed 78 inches wide; the current price list is the document Westin orders from, so 77 inches is the published figure.

What is the difference between a King and a Split King?

Construction, not footprint. A king is one solid mattress about 77 by 79.5 inches; a split king is two Twin XL mattresses, each about 38 by 80 inches, sitting side by side on two synced bases. The split gives each sleeper independent head and foot adjustment and a seam down the middle; the one-piece king is seamless but moves as a single surface. On a Harmony base the split king option Westin sells is the Harmony Relax Firm Mattress Split King.

Can I use a king mattress on an adjustable bed?

A flexible foam mattress like this one can bend on an adjustable base, but a one-piece king flexes as one surface: raising the head raises it for both sleepers. Couples who want independent positions need a split king, which is two Twin XL mattresses on two synced bases. Westin sells the Harmony bases in Twin XL, Queen, and Split King settings; there is no Harmony king base.

Is this the same size as a standard king mattress?

Almost. A residential Eastern King is 76 by 80 inches; this mattress is cut 77 by 79.5, one inch wider and half an inch shorter. King flat sheets fit without trouble; with fitted sheets check the pocket width, because that extra inch is exactly where a tight fitted sheet runs out.

Is the Harmony Relax made in Canada?

Yes. Harmony's product page for the Relax states it is crafted in Canada, and the line carries the made-in-Canada mark there.

How much weight does the mattress hold?

Harmony rates the Relax sleep surface at 350 lbs. The Harmony Hi-Low bed underneath lists an 880 lb lift capacity that includes the mattress and the people on the bed. If the sleeper weighs more than 350 lbs, the 600 lb Harmony Relax XC line comes in Twin XL, Full XL, and Queen; call us at (905) 451-7743 and we will check which width fits the bed.

How thick is the mattress?

10 inches, in three layers: 2 inches of GelFlex cooling foam, 2 inches of firmer rebounding memory foam, and a 6 inch firm core.

What sheets fit?

King flat sheets fit the 77 by 79.5 inch surface easily; fitted king sheets vary by brand against the 77 inch width, so check the fitted width before buying.

Can I use it on another bed frame?

Harmony designs and tests the Relax on Harmony adjustable bases, and the base layer's flex points match those bases. It is sized like a consumer mattress, so it also sits on a flat frame in the same size. If you have a different adjustable base, call us and we will check the fit with you.

Does OHIP or ADP cover this mattress?

No. Ontario's Assistive Devices Program does not cover mattresses, and OHIP does not either. March of Dimes, Veterans Affairs Canada, or a community support program may help depending on the situation. Our funding page explains the routes we work with.

Can I buy the mattress on its own?

Yes. This page sells the mattress by itself. It is a standalone product: no Westin Harmony bed ships a king width, so there is no bed bundle to add it to.

What is the warranty?

A 10 year limited manufacturer warranty for the original purchaser. Westin Healthcare handles warranty service through our service and repairs department.