Harris Bipod Adaptor for the M4 Battle Rifle. These are picatinny or weaver rail mounting adaptors to install the Harris bipod on the M4 rifle forend picatinny rail system and similar tactical set-ups. Very popular with AR15 style rifle shooters! The M4 Adaptor attaches to your M4 forend rail and provides a solid swivel stud to mount your Harris bipod on. - Note the beefy aluminum construction... Battle Proven in Iraq and Afghanistan. - Note the large thumbscrew allowing installation and removal in the field. - Note that its the same size as rail cover panels... It goes with the system! We have more adaptors and bipods at our Harris Bipod Home Page!