2-22 mm Taper Gap And Slot Gauge
A 152 mm taper gauge. The 3 mm thick blade widens by 1 mm for every 6 mm of length, from 2 mm at the tip to 22 mm. Grooves across the blade mark every 1 mm of width, with wider grooves at 5, 10, 15 and 20 mm. Slide it into a window-balance jamb channel, a bike dropout slot, a vacuum wheel fork or a door-check bracket until it stops, then read the width off the grooves. That gives you the size to order or model a replacement shoe, bushing or wheel. The handle is 5 mm thick and has a 5.5 mm hole for hanging it on a nail or pegboard.
tool gauge measuring taper-gauge