Promax C-1 Chain Tensioners Color:Black it uses 1 1/8" bearings

it uses 1 1/8" bearings to fit into the frame while the inner sleeve is made to fit 1" forks

Stack Height: 20

SIZE: 1" and 1-1/8"

Hub Type: Rear

Single adjustable belt for maximum fit and comfort

Promax C-1 Chain Tensioners Color:Black it uses 1 1/8" bearingsThe Promax C 1 Chain Tensioners at J&R Bicycles are a lightweight and affordable way to maintain a taught chain while securing your rear wheel and dropouts. Made from extruded and CNC machined 6061 T6 aluminum alloy, these tensioners are strong without adding much weight to your frame. The two hole axle design fits 3 8" and 10mm axles. Sold in pairs. FEATURES CNC machined 6061 T6 aluminum For use with 3 8" and 10mm axles Two axle hole design