The 1522KL is a Health-o-meter innovation! The sanitary child tray is made of sturdy ABS plastic and includes a built-in measuring tape (23 in., 59 cm). The physician balance beam of the 1522KL is easy to read with it's rotating kilo/pound beam. Durability of the 1522KL is built on maximum-strength, unitized 3/32 in. steel, low-profile, non-tip base with steel boxed levers and 3/16 in. hardened pivots and vee bearings. The base and lever system are constructed of heavy-duty steel. Rotating poise bars for dual reading of pounds and kilograms. Poise bar lock-in for error-free operation.