Using this allows Changing the Cam Timing Chain to be replaced without the Labor Intensive process of removing the Flywheel and the Gears behind it.After removing any (1) pin out of the Old chain, wire tie both ends so they don't drop down. On the New chain also press (1) pin Almost out, making sure to leave that pin attached to the Last Plate. This makes connecting the New chain together much easier to start the final press.Now wire tie the Old Chain to the New Chain and give it the same gap so you can rotate the Crank, Out with the Old, In  with the New. Bring the 2 ends of the New chain to the highest point, remove the Connecting wire and Align both ends together by placing the Press Tools hollow threaded tube over the Pin that is still in the Last Plate.Once the New chain pin is push in place, it will be tight, simply insert a small tip flat blade screwdriver (or similar) inside the plates that are tight and wiggle until the Chain is free again. It may take an extra tool to help. No peening of the pin ends is needed.You just saves about 2-3 hours of work and no Gasket or Flywheel puller to purchase.