4pcs 12mm Universal Dia Hole Chain Adjuster Block Tensioner Metal Silver Tone

[Specifications] Size: 37x31x17mm / 1.46″x1.22″x0.67″(L W H), Hole Size 1: 12mm / 0.47″, Hole Size 2: 27mm / 1.06″, Adjuster Block Tensioner Length: 7mm / 0.28″. [Chain Adjuster] Make your wheel chain tighter and not easy to fall off and if the chain is loose, you can adjust the wheel chain with the adjuster.