The stuff in the middle of a bearing

Hi Does anybody know where I can get a length of the plastic tubing that is supplied with the bearings for ball screws? I had a piece that I was going to use, but I had to destroy it to get it off the shaft after transferring the bearing from it. The actual size is about 14.6 ID * 17.6 OD with a wall thickness of 1.5 mm. I want to rebuild the bearings, but I need the tubing to hold the bearings in place.