Workhorse
This is the tool you will find in more Pro mechanics toolbox than any other. Solid construction and everything is all together - so you never have to scratch around for the cassette lock ring tool or the breaker bar. If you change cassettes a lot, you need this - it simplifies everything and the feel is just perfect.
The Dual Sided Thru axle version features a standard Shimano facing on one side and the 12mm axle compatible facing on the other, with the thru axle sided getting a larger guiding pin
The dual sided features tool facings for Shimano / SRAM and Campag cassettes. This is great if you are working with MTB and Road allows everything to be in one place.