A pressed aluminium dome sized for 76mm tube, and the most compact option in the range. It is the go-to for small catch cans, breather pots and compact surge tanks tucked into a wheel arch or behind a bumper where a larger diameter simply will not fit. The formed dome gives a rounded, finished end without hammering or rolling flat plate, and the machined weld face lets you tack and run a bead straight onto the tube with minimal preparation. Two domes and a short section of tube make a neat, fully welded vessel that looks like a purchased part. Popular with builders wanting a tidy under-bonnet installation without the bulk of a bigger tank.