LABELWORKS PX Heat Shrink Labeling Tape is made of a durable, flame-retardant polyolefin base makes them flexible enough to be mounted on curved surfaces. These labeling heat shrink tubing comply with UL Standard 224 standards, have a rated voltage of 300V, and a VW-1 flame resistance grade. Also, PX heat shrink labels are rated up to 125°C.This Labelworks PX heat shrink tube (EDMO# 221STBYPX) is black on yellow, 7/8 inch (21 mm) wide, and 8 feet long.