Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 2156-123P-PDA-1 found under Indicator Humidity Plug by Clariant Corporation. The National Stock Number assigned to this part is 6685011819998, 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 2156-123P-PDA-1.