Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number XANAX 0.5MG 500S found under Alprazolam Tablets by Pfizer Inc. The National Stock Number assigned to this part is 6505011969501, 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 XANAX 0.5MG 500S.