Wingsmoto Roller Performance 4 Gram Weights 16X13 GY6 50 139QMB 49cc 50cc Scooter Moped Jonway Dropship Roller Size: 16mm(outer dia) 13mm(height) For GY6 50CC Engine we have 4g, 4.5g, 5g, 5.5g, 6g, 7g weight. Weight: 4 Gram Package: 1set, 6 Pcs