This tape measure is a white, hard-wearing steel tape, tape width 16mm, scale in millimetres, with ABS plastic casing. Combined measuring and marking edges that quickly and easily measure and mark both external and internal lengths. The tape and extender can be replaced and are available as spare parts. The tape also measure diameters using the scale on the reverse of the tape and it also has a compass function which is useful when marking round shapes. The scale is always locked in normal position and the extender is easy to open out and retract with the easy-to-hold sliding carriage. Internal and external measurement using etching function Tape is made of impact resistant steel with ABS plastic case housing The tape measure has a calliper function that is handy to mark out round shapes The scale is always locked in normal position..