ZEV Technologies innovative product line now has an extended base pad for the standard capacity Glock magazine. Their 3-piece design is easy to reassemble onto the magazine and can be easily disassembled for cleaning without losing any parts.DOES NOT WORK with 10 round capacity magazines.Magazine not included.Kit contents: Basepad assembly (3 piece) Basepad baseplate Extra power magazine spring Technical specs: Adds +5 capacity on 9mm Adds +4 capacity on .40 cal Fits standard capacity Glock 9mm & .40 magazines Additional power spring provided Available in Red and Black anodized aluminum