GM-50912 is a set of 3 tools that correctly install and compress the solid Teflon seal on the stator shaft. GM-50912-3 is a 3.5" long, 1.9" OD smooth tube that covers the end of the stator shaft, protecting the seal from damage as it slides over the splines of the shaft. GM-50912-2 has expandable fingers that snugly fit the protector and evenly push the seal down the protector into its groove on the shaft without over-expanding the seal. GM-50912-1 features a tapered ID that gradually compresses the seal to the correct OD, ensuring it fits snugly inside the torque converter hub without being nicked or cut.