There are several different makes of teflon-insulated CAT5 cables ... as well as innumerable PVC-insulated CAT5 cables.
Belden - I think it is #1805 ... go search on their Web site - is bare Cu with teflon. Other makes (and other Belden wire products) have tinned-Cu, teflon-coated CAT5.
NB: Teflon-coated CAT5 is called "Plenum rated" - ie. the cable can be put inside heating ducts (plenums). As distinct from "normal" PVC-coated CAT5 cable which needs to be put into its own ducting, as PVC has a lower melting point than teflon ... so can't be exposed to heat.
Bare Cu wire is better sonically than tinned-Cu wire ... according to the esteemed Jon Risch (of AA).
Happy listening,
Andy
