Invigorating rubber surface with diverse massage textures targets pressure points. Elevates feet & legs to help relieve lower back pressure & improve posture. Free-floating platform allows for intuitive rocking motion to help promote lower leg movement. Scissor motion height adjustment provides three platform height settings (4", 5 1/4" & 6 1/2") & up to 25 tilt. Width: 17.88"; Height: 4" to 6.5"; Depth: 13.25"; Color(s): Charcoal / Blue / Gray.