The 3-4 person Model 4000 features a lounger and is designed and engineered for comfort, quality and performance and well equipped with many standard features. All Serenity Hot Tub models are ergonomically designed for full body support and comfort. Soft, comfortable pillows gently support your head and neck, while wide lumbar support seats cradle your body. Serenity’s unique “Versa massage” hydrotherapy system adds the final touch, massaging every inch of your body. A Serenity Hot Tub boasts a wide variety of stainless steel jet sizes and types from powerful wide body streams to penetrating finger tip massage, each jet individually adjusts to deliver optimum hydrotherapy.