This is a great harness for your service truck or in service on a machine. 
It’s difficult to find these but they are produced for Caterpillar. I’ve kept one in my service truck for years. It’s great for troubleshooting machine systems. You can install it on any machine temporarily while you wait for a PM400 to become available or leave it on there indefinitely. One of these little beauties can save you quite a bit on a new installation too.