www.roller-revolution.com

This new bearing is similar to the original Bones® Swiss bearing, but with a redesigned inner race and two labyrinth seals to keep dirt out even better than before. Bones Labyrinth shields are non-contact, so that they do not increase friction, only the distance dirt particles must travel to get past the shields. The only difference you will notice is that the labyrinth shield Bones will last several times longer than the original Bones Swiss between cleanings. This significant increase in service life comes at a very small increase in retail cost, so the value is greatly increased.

Priced for a set of 16.