Spa Fitter

Master Spas CS Windsor Replacement Cover

The Master Spas CS Windsor takes the AIRCAP 1™ X-Large — a foam-free replacement hot tub cover for square spas 92"–94". The CS Windsor's cabinet measures 94" x 94", inside the X-Large's range. The cover weighs 35–40 lb for life, costs $1,195, is engineered to comply with ASTM F1346-23, and carries a 3-year limited warranty.

Top-down view of the Master Spas CS Windsor hot tub — 94" x 94" square cabinet
Master Spas CS Windsor, seen from above — a 94" x 94" square cabinet.
Spa cabinet94" x 94"
AIRCAP 1™ sizeX-Large fits 92"–94"
Cover weight35–40 lb — constant for life
Price$1,195, free US shipping
SkirtZiptech™ modular, three lengths included
SafetyEngineered to comply with ASTM F1346-23
Warranty3-year limited warranty
AIRCAP 1™ — the Lightweight Hot Tub Cover by thrml. — fitted on a hot tub on a paved backyard patio at sunset, beside a fire pit
The cover you’d order AIRCAP 1™ X-Large (Fits 92"-94" Spas) Deep Grey™ $1,195 — free US shippingSKU AC6004 · UPC 850084423031

Why the X-Large fits the CS Windsor

The AIRCAP 1™ comes in six sizes covering square spas from 77" to 94". Each size is built to overhang its band slightly — that is how a spa cover is meant to sit — so the X-Large, which fits cabinets 92"–94", covers the CS Windsor's 94" x 94" shell with the right overhang.

At 94" the CS Windsor is at the top of the X-Large's 92"–94" range — the largest cabinet this size covers. It is also the largest square cover we make. Within Master Spas, the CS Windsor shares that 94" x 94" cabinet with Balance 8, CS Portsmouth, HL 8 and HL 8 DL — same footprint, same cover. Master Spas builds the 45 models we fit on 4 footprints, and the CS Windsor is on the largest of them; the line spans 4 of the six AIRCAP 1 sizes.

Cabinet dimensions can change between model years. Before ordering, measure your CS Windsor at its widest point across the top, in both directions, including any acrylic lip that overhangs the cabinet — the SureFit™ guide walks through it in two measurements. If a figure you have found elsewhere is larger than ours, an overhanging lip is the usual reason. If your spa measures between two sizes, round up.

Every spa in our catalogue that measures 94" x 94" is on one page: hot tubs that take a 94" × 94" cover — the same AIRCAP 1™ X-Large, at the same price.

How the AIRCAP 1™ is built

Instead of a rigid foam core wrapped in vinyl, the AIRCAP 1™ uses welded drop-stitch construction: a sealed air chamber with no foam to absorb water, so it does not become the waterlogged two-person lift that ends most foam covers. More on how it insulates, how it holds up, and why it is foam-free — or estimate what your current foam cover weighs.

Every Master Spas model we fit

ModelCabinetAIRCAP 1™
Balance 6 78" x 78" XX-Small
Balance 6 CS 78" x 78" XX-Small
HL 620L 78" x 78" XX-Small
HL 630L 78" x 78" XX-Small
L6 78" x 78" XX-Small
LH 6 78" x 78" XX-Small
S6 78" x 78" XX-Small
TS 6.2 78" x 78" XX-Small
Balance 7 84" x 84" Small
CS Cape Cod 84" x 84" Small
CS Exeter 84" x 84" Small
HL 7 84" x 84" Small
HL 7.5 84" x 84" Small
LH 7 84" x 84" Small
LH L7 84" x 84" Small
LH S7 84" x 84" Small
LSX 700 84" x 84" Small
LW 730L 84" x 84" Small
LW Enterprise 84" x 84" Small
LW Inspire 84" x 84" Small
MPL 700 84" x 84" Small
Precision 7 84" x 84" Small
TS 7.2 84" x 84" Small
TS 7.25 84" x 84" Small
Bar Harbor LE 86" x 86" Medium
Bar Harbor SE 86" x 86" Medium
Balance 8 94" x 94" X-Large same cover as the CS Windsor
CS Portsmouth 94" x 94" X-Large same cover as the CS Windsor
CS Windsor (this page) 94" x 94" X-Large
HL 8 94" x 94" X-Large same cover as the CS Windsor
HL 8 DL 94" x 94" X-Large same cover as the CS Windsor
HL 8.5 94" x 94" X-Large same cover as the CS Windsor
LSX 30 94" x 94" X-Large same cover as the CS Windsor
LSX 800 94" x 94" X-Large same cover as the CS Windsor
LSX 850 94" x 94" X-Large same cover as the CS Windsor
LW Acclaim 94" x 94" X-Large same cover as the CS Windsor
LW Intrepid 94" x 94" X-Large same cover as the CS Windsor
MPL 800 94" x 94" X-Large same cover as the CS Windsor
MPL 850 94" x 94" X-Large same cover as the CS Windsor
MPL LSX 30 94" x 94" X-Large same cover as the CS Windsor
Precision 8 94" x 94" X-Large same cover as the CS Windsor
TS 8.2 94" x 94" X-Large same cover as the CS Windsor
TS 8.25 94" x 94" X-Large same cover as the CS Windsor
TS 8.3 94" x 94" X-Large same cover as the CS Windsor
TS 8.35 94" x 94" X-Large same cover as the CS Windsor

All Master Spas models in the Spa Fitter

Master Spas CS Windsor cover: common questions

What size hot tub cover fits the Master Spas CS Windsor?

The Master Spas CS Windsor takes the AIRCAP 1 X-Large, which fits square hot tubs measuring 92"–94" across. The CS Windsor's cabinet measures 94" x 94", inside that band. Measure your spa side to side across the top of the cabinet to confirm before ordering.

Will the AIRCAP 1 fit a Master Spas CS Windsor?

Yes — the CS Windsor's 94" x 94" square cabinet falls in the AIRCAP 1 X-Large's 92"–94" range, and the Ziptech modular skirt system ships with three skirt lengths so the drop over the cabinet adjusts without a custom order. Cabinet sizes can change between model years, so confirm with two quick measurements.

How much does a replacement cover for the Master Spas CS Windsor cost?

The AIRCAP 1 costs $1,195 in every size, including the pump, three Ziptech skirt lengths, and tie-down straps, with free US shipping and 30-day returns. Unlike a foam cover it has no foam core to waterlog, so it stays at its original 35–40 lb weight for life.

How heavy is a replacement cover for the Master Spas CS Windsor?

The AIRCAP 1 X-Large weighs 35–40 lb and keeps that weight permanently — its sealed drop-stitch air core cannot absorb water. A foam cover starts at 40–75 lb and gains weight as the foam saturates.

Not a CS Windsor?

The Spa Fitter matches the current models of every major brand to the right AIRCAP 1™ — or measure any square spa with SureFit™.