Designed for use on beds with box springs and mattress, two long arms slip under the mattress giving secure retention. The rail part can be removed during the day by simply depressing spring clips. The bed rail folds flat for storage or transporting and can be reassembled in seconds without tools. Chrome plated 7/8" and 1" steel tubing. Each side sold separately. The height and width are adjustable. Width adjusts from 36" to 60" (91 - 152cm). Height adjusts from 14" to 18" (36 - 48cm).Width between rails 4" (10cm). Weight 8 lb. (3.6kg). Optional Bed Rail Pouch available - see below.