Features: Made of quality aluminum-alloy and stainless steel material. Lightweight and durable. Function: Solve the problem that the central axis sleeve is easily separated from the central axis when your force cannot be fixed. It can effectively reduce the maintenance timing and improve the maintenance efficiency of the central axles. Wide application: suitable for mountain bikes, variable speed bikes, etc. It is an important bicycles accessories. The locking mechanism introduces additional force to ensure tight contact between the socket wrench and the BB cup, avoiding damage to the BB contact outsides due to slippage during BB removal operations. Specifications: Material: Aluminum-Alloy+Stainless Steel Color: Black/Red/Golden/Silver Package Weight: approx.40g Size: As The Picture Shows Package Includes: 1Pc x Bikes Square Hole Anti-Drop Tool note: Please allow 1-2cm error due to manual measurement. Please make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thanks!