White Industries is making the strongest, most-durable freewheels around. This is their newest - the "Dos Eno" - a 2-speed freewheel. This freewheel allows the rider a choice of gearing, without having to switch freewheels. Just loosen the chain, move the chain, and re-tighten! 16/18 teeth, 17/19 teeth - fits standard freewheel threads. Serviceable, re-buildable and BUILT TO LAST! Made in the USA!<p></p> <p><strong>White's ratcheting mechanism has 36 teeth in which three pawls engage. Another leading brand has 20 teeth and two pawls ... you do the math!</strong></p>