Economy Pulley Set : Band drive

Seven-piece set: Nylon with 6 bands Quantity/ Size (Bore) ~ 1 x 10mm (2mm) ~ 2 x 12mm (2mm) ~ 1 x 15mm (4mm) ~ 1 x 20mm (4mm) ~ 1 x 25mm (4mm) ~ 1 x 30mm (4mm)Use as track wheels and pulleys for your own inventions. Fits 4mm & 2mm axle rod SR40 & SR20 & PSU prop-shafts.