#279 Smoke Spec (does not include lenses) The #279 Smoke Spec insert fits most full-facepiece respirators. Click here for the Smoke Spec Insert Guide for examples of compatible masks. Click here for insert specs. Instruction Page. #279 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 Prescription Bifocal LensesPer Pair – Free USPS First Class Shipping – (Near vision segment = 28 mm wide x 19 mm high) $95.00 Add to cart