I bought mine from Microtools and am very pleased with it. I can't remember the model number off the top of my head but it's the one with the set screw holding the blades in place rather than the quick release.
Other than having to file the tips very slightly to fit the older rangefinder retaining rings it's been fantastic.
I've used the models with the spring loaded ball bearings holding the tips in ... I'd stay clear of them. They don't hold very well

dan