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Spa Fitter

Master Spas LSX 850 Replacement Cover

The Master Spas LSX 850 takes the AIRCAP 1™ X-Large — a foam-free replacement hot tub cover for square spas 92"–94". The LSX 850'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 LSX 850 hot tub — 94" x 94" square cabinet
Master Spas LSX 850, 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

Why the X-Large fits the LSX 850

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 LSX 850's 94" x 94" shell with the right overhang. Instead of a rigid foam core wrapped in vinyl, the AIRCAP 1™ uses welded drop-stitch construction (the material of premium inflatable paddleboards): a sealed air chamber that cannot absorb water, so it never becomes the waterlogged, two-person lift that ends most foam covers.

Cabinet dimensions can change between model years. Before ordering, measure your LSX 850 side to side across the top of the cabinet in both directions — the SureFit™ guide walks through it in two measurements. If your spa measures between two sizes, round up.

Other Master Spas models we fit

Not a LSX 850?

The Spa Fitter matches 363 models across 25 brands to the right AIRCAP 1™ — or measure any square spa with SureFit™.