Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 243-20005-05 found under Filter Element Set Chemical Biol by Ilc Dover Lp. The National Stock Number assigned to this part is 4240013406314, and the Federal Supply Class is 4240 Safety And Rescue Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 243-20005-05.