Used to lock the engine up when replacing the camshaft drive belt and also the chain in the cylinder head. 
These engines have both a cam belt, and a timing chain inside the cylinder head.
The majority of the time you will be replacing the belt only, unless you are pulling camshafts out or the cylinder head off.
This kit will do both the belt and the chain when doing the cylinder head chain.

Models: Holden: Commodore / Calais (ZB) Opel: Insignia / Zafira
Engines: B20DTH (LFS)
OEM: EN-51411 / EN-51412 / EN-51413-2  / EN-51414 / KM-955