Trim-Tex Vinyl 3/4 in. Square Bullnose Adapter A rust-proof dent resistant PVC molded adapter that transitions bead to a 90° corner for installing baseboard. Benefits: Does not contain cellulose, a food source for mold. Achieves Class A rating for flame spread as per ASTM E84 standards. Self-extinguishing when source of flame is removed. Can be used with Trim-Tex 847 Spray Adhesive. Trim-Tex Vinyl Corner Bead products are designed for interior use.