The Gundlach 25-AB Airway Straight Blades are trapezoidal-shaped, reversible utility blades designed specifically for use with the Gundlach No. 6 Airway Knife (also compatible with the Crain No. 025A). Each tube contains 12 blades, which feature a square central cutout that fits onto a square boss in the knife handle to eliminate blade wobble during use. These specialty blades are primarily used in vinyl, linoleum, LVT, and VCT flooring installations, where precision and durability are essential.