BOX Box Two Freewheel, 18t
– Box Two™ freewheels combine durability with lightning-fast engagement – They feature nine, super durable pawls and are available in 16, 17 or 18 teeth – To install, use installation tool designed for single speed freewheels with four notches that are approximately 32mm across measured inside to inside and 40mm outside to outside – Fits 1.375 x 24 TPI hub thread – Fits 1/8″ or 3/32″ chain.