SRAM's UDH (Universal Derailleur Hanger) has been widely adopted over the last few years as brands look to give customers and retailers a simpler solution when it comes to sourcing spare hangers. It makes a lot of sense if all brands use the same hanger, sourcing a spare from either a shop or at the trail side in an emergency is much easier.
SRAM has since revealed its full hand with the release of its T-Type Transmission which, handily, is only is compatible with the UDH standard. Part of Revel's recent Ranger update was moving to UDH hangers, they have now gone all in with a sweeping update across almost all their bikes to make them compatible with UDH.
