Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 1R4305 found under Retainer Dehydrator Screen by Drs C3 And Aviation Company. The National Stock Number assigned to this part is 4440016110032, and the Federal Supply Class is . Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 1R4305.