Saris’ smart trainer lineup has seen some fluctuating naming and specs of late, and the newest H3 Plus combines the best of the prior H3 and the now-defunct H4. It also gets a helluva lot cheaper. The H3 Plus takes the perfectly flat driveside shell design of the H4, making it compatible with modern Shimano and SRAM 12-speed drivetrains, with cassettes up to 42-tooth. The prior H3 had a slight curve to the shell that could interfere with the derailleur hangers on 12-speed setups, but the flat profile makes space. More space, actually, as the H4 was rated to fit 32-tooth cassettes.