There are not too many high grade bearings out there which are built to withstand an honest day's skate. The Bones Super Swiss 6 Ball Bearings are one of them and have been rigorously tested by the skateboarding industry.

What makes these so good? Most bearings use 7 small balls. The Bones Super Swiss 6 Ball Bearings only use 6 larger balls. This increases the strength of the bearing and reduces its friction. Perfect if you need to go fast, ride smooth and/or casually jump off a roof or two. 

There is also a worldwide understanding that bearings made in Switzerland are just legit.

Sold in packs of 8 (please remember; your wheels take 2 bearings each so you will need two packs of bearings to fit 8 wheels)