Product details:

For use with the typical hydraulic floor jack that has a removable pad with a 1-3/8 center hold. Remove the pad and replace it with the transmission adapter and you have a secure 12 x 12 surface to hold the transmission steady during installation or removal. Three sides have a 1 lip to keep the transmission in place and a front opening for sliding the transmission on and off the engine dowel pins. This popular adapter makes a perfect pit tool.