- Alps2Ocean Diamond-Crank 102 mm crank arms, made from forged 6061-T6 aluminum alloy for maximum strength and durability - Black sand finish that provides a modern and elegant look - Compatible with city, mountain (MTB), electric, folding, road, junior, and stationary bikes - Square tapered spindle interface with diamond hole, 12 cm diameter - Includes two crank arms (left and right) and bolts for secure installation - Each arm is clearly marked (L and R) to avoid installation errors - Recommended for those looking to upgrade or replace their bike's crank arms with a strong and reliable product - Easy to install, just make sure the hole type and length are compatible with your bike