#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 Reading LensesPer Pair – Free USPS First Class Shipping – (Reading vision segment 28 mm wide x 19 mm high) $45.00 Select options Anti-Fog Lens CoatingPer Pair – Free USPS First Class Shipping – (Smoke Spec lens orders only) $65.00 Add to cart