OEM Length of Pull Extensions for FRS-15 GEN III Rifle Stock.Our length of pull extensions are 1/2" thick each. With the 4" screws that came with your stock kit, a maximum of 7 spacers (including transition plate) can be used with the FRS-15 GEN III to achieve a 15" length of pull.KIT INCLUDES: Four spacersSPECIFICATIONS: Stackable up to 7 spacers Weight: 6.03 oz. Injection molded polymer Available in three colorsMADE IN USA