It is simple, very leightweight and can be adjusted to the needs of every individual plane firewall, engine, nose gear etc. I am using the same kind on a OS .61 RF-P, the Al-Plate has just a hole in its center to make room for the pump. I have come down to 1,5mm thickness of the Al-plate, earlier I made it 3mm but that is just oversized for a .61-engine.