There is a load of information on the pure power site (
www.gopurepower.com). It's basically a washable re-usable oil filter with a lifetime warranty.
Expensive, but I thought my Z deserved the best and it looked like it was going to be a pain getting oil filters up here anyway.
Vette magazine also did a write up on them, last year I think, with positive results (
http://www.vetteweb.com/tech/vet_050...st_oil_filter/ ).
They didn't list a specific ZR-1 filter last time I looked, but I emailed them and they came back with the right specs, I've had no problems at all with mine and it's comforting knowing that I'm getting good filtration. It's also amazing how much rubbish that it pulls out on the first couple of 'changes'.