Curt, there was a description of the variations of RH Timers by Richard Ross in this thread a few months ago -

I have recently bough a Stopclock Pro after everybody at an APUG get together in the UK strongly recommended it - actualy everyone but Richard Ross - he is too nice a guy to push his own stuff

Actualy when I bought it I was a little sceptical about the benifits but having used it I have been won over and am very impressed.

With 2 seperate timer channels the Stopclock Pro was designed for split grade printing - one for Filter 0 and the other for Filter 5

Its also very user freindly and very intuative to use

The RH Designs web site is full of useful stuff about the products and he is a realy nice bloke if you want to contact him directly