Bought 12/28/2025 to build new S-Works Aethos 2 frameset as a 1x with only one battery for the drive train. It is actually a MTB derailleur though we got it to work with Dura Ace 11-34 cassette and Shimano 11-45 cassette. In the end realized too heavy (469g w/battery) and bulky for slim Aethos. DA 12 sp derailleurs with battery is 100g lighter! So went to 2x. XT derailleur like new only 7 scratches on back where adjusting touched the largest cog on the bike stand. Original cost: Derailleur $570; battery $55; charger $45 = $670.