That's the Shimano XT M8000 11-40 cassette. Also comes in 11-42 for a slightly lower gear. Rumor is Shimano will come out with an 11-46 at some point soon, but too low for my needs. Really more for MTBers. The new SRAM 10-50 has a crazy wide range (500%) but is cost prohibitive. Looks like the 1x drivetrains will soon offer a derailleur-based option with a range comparable to the Rohloff Speedhub, at a lower cost and weight.