http://www.focalprice.com/LF933O/FENIX_AD202_Traffic_Wand_Flashlight_Accessory_Orange.html
Not sure how much of a deal it is, but it's the cheapest I found.
Anti-impact and anti-heat, super durable, can be used in bullet-proof applications
i have it it's great!!
days ago i ordered the Fenix diffuser lens, with the black plastic ring as seen here:
http://club.dx.com/reviews/photos/52511/150263
very cheap at DX. (i ordered it from HKE.)