The FAB Defense Rubberized Pistol Grip for M16/M4/AR-15 does not include any hardware. You will have to re-use your original hardware, or you can purchase the ATI AR-15 Pistol Grip Screw and Star Lock Washer, linked below:
https://www.opticsplanet.com/advanced-technology-international-ati-ar-15-pistol-grip-screw-and-star-lock-wash.html