Thank you for selecting Aerospace Aviation 360 for BT4-IR by Starline under Circuit Breakers. We are proud to be an ASAP Semiconductor owned and operated website, a leading distributor of aviation and aerospace part numbers like BT4-IR. To help us better understand your parts requirements, please fill out an RFQ form for part number BT4-IR with your details, and our customer executive will respond to your RFQ in 15 minutes or less.