The Rollameter100 is an inexpensive100cm [1m] “mattress” designed to allow any infant not yet able to stand straight to be measured lying down [supinely] to the nearest 1mm – a lightweight, portable, non-stretch, non-shrink, hygienic device of closed cell plastic foam, it is designed to be rolled up for storage when not in use.
See MEASURE MAT for a rough-and-ready supine measurement to the nearest ½cm.