Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 20X25X4 found under Filter Media Air Conditioning by Engineered Air Systems Inc. The National Stock Number assigned to this part is 4130001847462, and the Federal Supply Class is 4130 Refrigeration And Air Conditioning Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 20X25X4.