ITEM NAME:10Pcs Aluminum Bullet Propeller Adapter Holder for Brushless Motor Prop Description: 100% Brand new and high quality Delicate workmanship, durable in use Suitable for brushless motors and speed controllers Material: Aluminum Color: Silver Specification: Motor Axle hole diameter: 3.17mm (5mm output shaft) 4mm (6mm output shaft) Quantity: 5pc 3.17mm, 5pc 4mm, 10Pcs in total. Size Chart: As described above, please make sure the information of size before making a order. Package Includes: 10 Pieces of Aluminum Propeller Adapters SKU: FUZ0016263919510216.10 Pieces of Aluminum Propeller Adapters. Quantity: 5pc 3.17mm, 5pc 4mm, 10Pcs in total. Material: Aluminum. Size Chart.