Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number HSM48 21 25173 PG6 7 REFQ4 5 found under Transistor by Kepco Inc. The National Stock Number assigned to this part is 5961001240117, and the Federal Supply Class is 5961 Semiconductor Devices And Associated Hardware. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like HSM48 21 25173 PG6 7 REFQ4 5.