And can be cut in any diameter a person desires. EDIT: IIRC the stock C/D Maglite lens is either acrylic or polycarbonate (but uncoated). I expect wear properties of the UCLp lens would be similar to a stock Maglite lens (very tough and fairly scratch-prone).
I have some 3mm Abrasion resistant acrylic that I could cut a disc from with a hole saw. I used it for a 35mm underwater lens. 57mm is ~ 2 1/4” so 2 /38” bit should be close or I could cut with a 2 1/2” bit and you could sand it tight. Yours for the asking.
I’d get plastic lenses but not let her use a HD2010 again, those are seemingly pefectly weighted for maximum drop probability and she’s already proven it will happen 
May I ask what she does with them??
I think you should shop for a hard hat.
hardhat lol … yep, life’s tough for the flashlights on the “farm” … Thanks for all the suggestions guys , it’s late now and we’ve been 3 days without power… generator only … will have to think/re-read about all this tomorrow … meanwhile I just received an awesome HD2010WW from Cereal_killer (which she will not be using for her rough duty chicken/geese shit duties - so I gave her my old 2010 ) Thanks everyone!! Will be getting new lens soon now thanks to you all …
I appreciate it !!
Cheers —
-S
I think polycarbonate would resist braking best.
Thanks You all. I stuck the flashlight in a drawer and completely forgot about it. I just ordered 5 AR lenses from cnqualitygoods - thanks for that link MRsDNF. And thanks for the offer Rufus but I decided on the AR coating. I ordered extra so’s when she breaks another one I’ll be ready … or maybe I’ll just hide them all from her 
Ahhh … after waiting seemingly forever for the lenses, they finally came in today…
less than a perfect fit for the HD2010 … grrr …
Bugger. Where did they come from?
I think it was cn quality goods. I’m sure they’re good quality, just the wrong size …
Do they measure 27mm x 2mm?
I saw the dropdown box that I musta forgot to change … that’ll learn me to be in a hurry … heh … ;/
Looks like you'll need to get a couple of extra lights to suit the new lenses not that that helps the current situation.
Yeh, that’s ok… I think it was only a few bucks for those and probably free shipping … I’ll just re-order and do it right this time …
What will 27mm lenses fit ?
I'm not sure what those lenses will fit and it appears they dont have the 58 or 57mm lenses in stock anymore. I may have a couple of stock lenses but I'm in Australia. Shipping would probably cost a fair bit?
well, I just ordered a couple of the 55mm ones… the aperture looks like 52mm… the o-ring will be too big now … probably will run a small bead of silicone RTV around to seal it in … press it in when it’s halfway set… hopefully will work … ?
Thanks for the offer though MRsDNF
They will fit in the Ultrafire and Solarforce P60 hosts.
PS: If it wasn’t that much for shipping, i would take ’em. 
I have a regular glass 2010 lens you can have if you pay shipping