Ecobra Master Giant Bow Compass (no extension bar)

Ecobra Master Giant Bow Compass (no extension bar) The Master-Bow features an unbreakable hoop spring, centre screw spindle with end stops and two Knee joints. The spigot diameter is 4mm. Length 162mm (6″) Working range 250mm (10″) diameter. Image shown is of model with extension bar. Not suitable for use with technical pens.