Hi SteveH,
first piece of advice is to use the search engine before posting a request. Saves some peeps moaning about repetitive posts.
There have been numerous threads, Re. Regulators in the past but here are a couple of web links to get you going;
www.airguns.net/reviews/regulators.html
Go back to the "parent" folder to finds loads of info.
www.warpig.com/paintball/technical/regulators/howtheywork/index.shtml
www.warpig.com/paintball/technical/shocktech/fgpreg.shtml
Both from a paintball site but absolutely stacks of info.
Go here;
http://gb.espacenet.com/
and plug in the number GB2372552 in the Publication number box
This is the new Theoben regulator in the MkII, I believe.
HTH,
Sandy