They are the things inside the neoprene wheels that mount to the shaft on a skateboard. They are called ball bearings; they make the wheels have less friction on the shaft or axle. You maybe able to see them if you look at the wheel or at least hear them work when you spin the wheel...I think when they wear out, you just buy new wheels with them already molded into them.
bearings r the things inside wheels that let them spin
first, try posting in the proper category (this is Cycling) second, most wheels have some type of bearings to act as the glide point between the hub or axle and the wheel itself
they are the 608. OD = 22mm, Thick 7mm. I forgot about the ID.
