Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number NDC00591-0491-01 found under Mexiletine Hydrochl by Watson Labs Inc. The National Stock Number assigned to this part is 6505012566367, 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 NDC00591-0491-01.