I believe the Lens replacement kit for these type of 1" diameter SureFire Bezels is the Z17.
If your Z3 Bezel looks like the ones in this Z Series Photo Gallery:
http://www.pk-engineering.com/flashlightZ2Z3.html
The M6
does have a LockOut TailCap (LOTC), and AFAIK, always has.
The latest versions of the M6 have body & TailCap idents allowing better use of the LockOut Feature.
The Millennium Series have not been produced with Lexan lenses for sometime now. Pyrex is used in the Millennium TurboHead and the Z44 & Z46 (M2 & M3) Bezels.
Now that I have a Pyrex lens version of the 10X, I don't have to worry about damaging [the old Lexan version]
Pyrex in SureFire's Bezels is very difficult to break - you're going to have damaged the Lexan version before you break the Pyrex version...
Pyrex is a fantastic improvement.
If you have any questions regarding SureFires, please do not hesitate to contact SureFire Customer Service, your friendly SureFire Dealer, or start a thread on the SureFire Discussion Board
http://186thousand.com
Al
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Administrator: CPF