Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number K157-12 found under Shaft Reverse Idler by Republic Gear Co. The National Stock Number assigned to this part is 2520004231778, and the Federal Supply Class is 2520 Vehicular Power Transmission Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like K157-12.