Which Oil Pressure Switch??

Hi Guys,

I'm a bit confused here, I ordered a Oil Pressure Switch from AB, and was sent the allmakes brand. Will this do the Job, being the landrover recommended type has the a washer and O-ring and my allmakes has just the washer with some black stuff on there.

The AB site Switch - Oil Pressure | Land Rover Electrical Parts, Batteries, Relays, Lamps & More shows the Washer and Oring, but what I received looked liked this http://www.rovahfarm.com/images/STC4104.png

What do you guys recommend...

Thanks