Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 8494-G502 ITEM NO.4 found under Filter Water Purification by Howell Laboratories Inc. The National Stock Number assigned to this part is 4610016176084, and the Federal Supply Class is 4610 Water Purification Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 8494-G502 ITEM NO.4.