TTX dampers come standard as a "2 Way" damper meaning compression and rebound have their own separate adjuster knob. Each knob is adjusting what is called a low speed "1 Way" valve assembly.
When expanding the adjustability of the damper, each 1 Way valve assembly can be swapped out for a "2 Way" valve assembly. These 2 Way valve assemblies have two adjustment knobs, a 3mm inner Allen socket that adjusts low speed forces and a 12mm outer hex that adjusts high speed forces.
Since these valve assemblies are all contained in the main body of the damper, all adjustments take place on the same area of the damper, no need to be at the shock for one adjustment and under the hood or in the trunk for a second adjustment at a canister.
