Thank you for selecting Aerospace Aviation 360 for K1S4 by Asea Brown Boveri Power T And D Co 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 K1S4. To help us better understand your parts requirements, please fill out an RFQ form for part number K1S4 with your details, and our customer executive will respond to your RFQ in 15 minutes or less.