basically a big cannister with a piston inside it, on one side of the piston there is air pressure (set to approx 20psi when empty) and on the other side is oil pressure. only one oil line to the cannister on the oil side, this is plumbed into the main oil gallery on the engine through the top of the block (you will see a m18 plug towards the rear of the block iirc). to fill the cannister you overfill your engine oil by however much the accusump holds, start the engine then shut off the tap that you have installed in the oil line. turn engine off and recheck oil level. Now this is the good bit, next time you go to start the engine, open the tap, watch your oil pressure guage come right up, then start the engine. How goods that, oil pressure to your mains and big ends before you even turn the key. It works by the oil pressure forcing the piston inside back, compressing the air on the other side, when for arguements sake, your cornering and the oil pickup comes uncovered, the air pressure (now 80-100psi) forces oil through the line and into the bearings maintaining a constant supply of high oil pressure.