want a 16 mm triple square xzn bit for your 5-speed transmission drain plug?
given that it's not a Porsche part per se, go to pelican; here's the part in the Porsche section:
Pelican Parts - Product Information: PEL-TOL-ST0229
and here's the part in the vw section:
Pelican Parts.com - 16mm XZN Audi/VW Drain Plug Socket
notice any difference?