E*thirteen Helix R Guidering(52/55 Flip Flop) 32t Intergale*thirteen Helix R Guidering 32t 11 12 Speed 52 55mm Flip Flop CL 3 5mm Offset e*thirteen DM Intergalactic. Helix R Direct Mount rings are designed to function equally well with all 11 and 12 speed SRAM and Shimano drivetrain systems on e*thirteen Helix or legacy TRS LG1 XCX cranks. e*thirteens Gen 4 narrow wide tooth profile delivers upgraded chain retention lower system noise and increased wear life Cross Compatible with SRAM and Shimano 11 and 12