4mm ID Non-Flanged Ball Bearing (16mm OD, 4mm Thickness) - 2 Pack

These non-flanged bearings are able to mount on either side of a structural component that has a width that is divisible by eight, while staying on pattern, to create a linear motion setup.  For example, these bearings are able to be placed on the top and bottom sides of the 1120 Series U-Channel, and mounted 64mm from one another.  The bearings will provide support to the channel, while allowing it to roll easily to create smooth linear motion.  Given the 4mm bore, they are able to be fastened using standard M4 screws.