These are manufactured in rugged, high-impact polymer. These pads are attached to 1911 single stack magazines with self tapping screws supplied. It is recommended to drill holes in the base plates prior to adding pads. The hole spacing is the standard .531" center to center, which is common on most all predrilled magazines. Extended pad is .550" long, it extends beyond the mag well to aid in positive seating for combat specialists or IDPA and IPSC competitors.