The 553-50029 is a ShrinkTrak™ heat shrinkable marker designed for printing identification labels for wires and other components. Made from flexible, flame-retardant, cross-linked polyolefin (PO-X), it features a 3:1 shrink ratio and has a pre-shrink outside diameter of 0.5 inches (12.7 mm). These thin-wall labels are supplied in a ladder-style carrier system for easy printing with thermal transfer printers and have a recovered wall thickness of 0.033 inches. The material is rated for an operating temperature range of -55°C to +135°C and meets UL 224 VW-1 flammability standards. Designed for indoor use, these military-approved markers provide a durable and legible identification solution for various electronic and electrical applications.