Brady PermaSleeve Heat-Shrink Polyolefin Wire Marking Sleeves (M21-187-C-342) - Black On White Sleeves - Compatible with BMP21-PLUS, ID PAL, and LABPAL Printers - 7' Length, 0.335" Width Made from Brady's B-342 Polyolefin PermaSleeve Marker material, a non-adhesive, heat-shrinking sleeve that fits around wires or cables for insulation and easy permanent identification. 3:1 heat-shrinking wire marking sleeve is ideal for labeling in harsh environments and is resistant to exposure to chemicals, grease, oil, and cleaning agents. Polyolefin wire marking sleeves print in black text on a white background with a smudge-proof finish. Permasleeve labels provide a wire marking solution that combines speed, ease of use, and permanence to create long-lasting, high quality identification Compatible with the BMP21-PLUS or ID PAL label printers, permasleeve wire labels are an indispensable asset for electrical contractors, maintenance crews, construction teams, and industrial professionals.