Rival AXS XPLR E1Perfect shifting through better design, even through the toughest gravel terrain. 1x specific for use with 10 46T XPLR 13 speed cassette and Flattop chains Hangerless Interface and Full Mount attachment allow for the most precise shifting and the ultimate resistance to impact Simple setup with no adjustment screws Superior chain management with MTB inspired spring clutch Replaceable and rebuildable parts Requires UDH compatible frame SRAM Model ID: RD