for inconvenient spark plugs, to be used with 3/8 "or 1/2" square drive or ø 8 mm wring bar
with strong mini magnets on the inside that hold the spark plug reliably in the socket wrench
the free intake space in the cap provides ample room for the spark plug and makes it easier to insert the socket, especially where accessibility is limited
no contact between the key and the ceramic material of the spark plug