Goplus Kneeling Chair, Ergonomic Posture Chair with 4” Thick Padded CushionASIN: B0CF9V9N5S 4" Thick Padded Cushion: For comfort, the 3. 5" thick seat and 4" thick knee cushions are filled with high density sponge and covered with breathable linen like fabric. When sitting, thick padded cushions provide better cushioning and reduce pressure on the knees and hips. Tip: The initial soreness is normal as the sitting posture is being corrected. Reduce Back Pain & Correct Posture: No more struggling with poor posture and back