THIS WILL MOUNT A PAIR OF PETERSON 400 SERIES FILTERS SIDE BY SIDE. MOUNTS TO A 1" TUBE, BAR OR 1" HARD LINE IN THE CENTER OR CAN BE MOUNTED TO A FLAT PANEL THE CENTER LOWER PORTION WILL REST ON AN APPROX 1.25" ROLL BAR, BUT THE LOWER HALF IS NOT INCLUDED TO MAKE IT A CLAMP MOUNT.