Fits 3 and 4 port GENUINE MAC valves with this ONE bracket ! Non tabbed (no cantilever) provides more secure mounting ,more compact, less possibility of vibration. Threaded , NO NUT /back protrusion design allows FLUSH Mounting to firewall etc. Screws thread into bracket and do not protrude past the rear surface. TWO rubber isolators included for maximum stability, reduces possibility of rotation. 6061 CNC'd Alluminum Alloy, not fragile plastic etc. Large hole as a tie point for strain relieving the wires. Fits 3 and 4 port GENUINE MAC valves with this ONE bracket ! May not fit counterfeit valves , not our concern. User should source the correct length M6 bolts for the rear (chassis mount side) of the isolator as each installation is different. Ace hardware etc. has what you need. Each isolator has steel female threaded inserts on each end. 2 different length PAIRS of stainless steel screws are included as different MAC valves have different thickness bodies, this way you can select the pair that does not protrude out the back side (remain flush).