Ella Acrylic Walk-in Tubs are vacuum formed from a solid, long-lasting acrylic sheet.Ella''s ShaK Walk-In Tubs main feature is the U-Shape Outward Swing Door made with industrial grade durable plastic composite material with a decorative tempered glass front screen. A 3-latch door system creates a more secure and watertight door seal, providing you with a safe, leak-free bathing experience compared to competitors 1-latch systems. The ShaK comes with our unique Ella Dual Drain Technology (DDT) consisting of two 2" gravity driven drains with four 2" outlets, 2 overflows and 2 openers. This system provides creates the fastest gravity driven drain in the industry. The Hydro Massage System includes: a hydro pump with an in-line water heater, eco-friendly ozone sterilization system, hydro massage intensity dial control, and strategically positioned hydro jet system for targeted and effective massaging.The Ella ShaK has twenty-one (21) strategically placed hydro jets in order to deliver optimal therapeutic relief. Fifteen (15) upper fixed jets work to provide relief to your back, hips and thighs, while six (6) lower adjustable jets massage your feet and calves. The Hydro + Independent Foot Massage package uses two independently run pumps to give bathers a simultaneous full body and foot massage. Or, bathers can enjoy an independent foot massage within minutes of simply filling the foot well up the seat level. The Air Jet Massage System includes an air pump with a 3-speed variable push control, strategically positioned air jets for optimal therapeutic relief, and an auto-purge to maintain an air system free of any build ups.The ShaK has sixteen (16) strategically placed air jets that pull in air and blow it into the water to create a gentle, relaxing massage. Twelve (12) upper jets work to provide relief to your back, hips and thighs, with an additional four (4) floor jets located in the lower foot area.