Used on a Shimano 105 5800 group set. Short cage, 50/34 up front with a SLX 11-40t cassette. 1 or 2 extra links in the chain cant quite remember. Works fine, just make sure you never change into the two big rings. But why would you anyway.
Easy to fit, gives you the option to have a couple big granny gears for when your totally dead in the legs.
34-40 is a stupidly easy gear, but with bags on the bike and 150 miles in the legs, it makes sense.