LERWAY A-05 11T Bike Cycling Bicycle Aluminium Jockey Wheel Rear Derailleur Pulley Guide Roller Idler 1 pcs Diameter: 5mm or 6mm Size: 11T Dimensions: 1.69 in x 1.69 in x 0.24 in (4.3 cm x 4.3 cm x 0.6 cm) Material: AL7075 CNC Machined Weight: 0.46 oz (13 g)