Porsche p/n 000-721-920-10
Here are a few notes on the (in)famous tool for tensioning the timing and balance shaft belts on the 944 and 968.
The lowest cost supplier in the US that I'm aware of is Sunset Imports. As of June 2003, the list price is $609 but Sunset Imports sell it for $455 (i.e. dealer cost +15% handling charge), not including shipping.
Naturally the factory manuals are the best for describing how to use this tool but they are expensive and are aimed at professional mechanics.
There are procedures available online. The best site I know of is Clark Fletcher's truly excellent Clark's Garage. It is a treasure trove of information and he has a documented procedure for checking & adjusting the timing and balance shaft belts.
To date, I've found two low cost alternatives that claim to be an alternative to the P9201. Personally I'd be very nervous about using them.
The Kriket I Tool from 9x Auto.
The Optibelt Tool from Blaszak Precision Motorsports.