The TE Connectivity / Raychem brand part 203A021-4/42-0 is a heat shrink molded boot made of flexible polyolefin material in a sleek black color. This durable and reliable boot is designed to provide protection and insulation for cables and wires in a variety of applications. With its high quality construction and ease of installation, this heat shrink boot is a must-have for ensuring the longevity and performance of your electrical connections.