Adaptive positioning provides stability & support for those lacking full body control. Firm comfortable foam wedges help proper positioning in the Prone & Supine position and for achieving greater gross & fine motor skills. Sizes of Wedges are:Elevation Base a, 15cm x 60cm x 70cm. b, 20cm x 60cm x 70cm. c, 25cm x 60cm x 70cm. d, 30cm x 60cm x 70cm. Wedge Features : Foam filled wedges covered with Nylon / Tetron. Fitted with Velcro strap to position the child. Comes with Add-on Leg Abductor Wedge, attaches with Velcro strip.