Special valveless radiator cap (non vented).
Designed for use on vehicles where a radiator or expansion or header tank cap is required which has no opening pressure valve.
Useful for modified cars which require a non-vented cap somewhere in the plumbing system.
Alloy filler neck.
Can be welded, brazed, or soldered to any brass, steel, alloy, or stainless steel radiator or expansion tank or pipe.
Available in 2 sizes:
standard radiator cap 11/4" opening ID with 1/8" breather
Japanese ("mini") taking 32mm radiator cap with 1/16" breather