Ideal for removing or installing injector nozzles Works on Bosch KDEL 21 mm injector nozzles used in John Deere engines You use the inner socket to hold the nozzle stationary and the outer socket to loosen or tighten the nozzle's gland nut OTC's tool is an affordable alternative to the hard to source John Deere injector tool High-grade materials ensure quality performance over the lifetime of the tool