Space Balls are patented spacers made from EPDM rubber and are designed to center solid panels on your cabinets doors. Because these spacers are made from rubber and can be compressed, they allow panels to expand and contract with the changes in weather without putting strain on glue joints. Space Balls also cut out most major call-backs on solid or flat panel doors and help eliminate panel rattle. Space Balls should fit snugly but not be compressed to more than 1/3 of their diameter in order to create the most reliable expansion joint. It is recommended to use 8 - 10 Space Balls per door. Pack of approximately 100 Space Balls fit .26" grooves and standard rail and stile cutters.