View cart “Prescription Bifocal Lenses” has been added to your cart. #276XT Smoke Spec (does not include lenses) The #276XT Smoke Spec insert with extension bracket. Click here for the Smoke Spec Insert Guide for examples of compatible masks. Click here for insert specs. Instruction page. #276XT Smoke Spec quantity Add to cart Category: Uncategorized Related products Prescription Single Vision LensesPer Pair – Free USPS First Class Shipping – $65.00 Add to cart Additional Anchor Bracket (does not include lenses) Add to cart