These pneumatics fittings I have were supplied from here:-
http://www.parkerhydraulics.co.uk
Handy for me as I live near Norwich
Some are from the Flowtech range and some from the Festo range. Sizes vary depending on what they are for.
It's worth pointing out that these fittings are designed to be used with the more rigid nylon/polyester pipe, not the more flexible plastic tubing, and as such more care has to be taken when using it in the PC, so as not to damage anything.
[ 09-18-2001: Message edited by: BladeRunner ]