Trans Kick takes the Kick bit’s angled, semi-flat profile and shrinks the tip diameter, then wraps it in a rotating plastic guard that locks against the ratchet. Twisting that guard sets the bit into either High Mode or Low Mode, each slightly off the standard height in the respective direction. The mechanism is not a switch you set and forget: the force of an Xtreme Dash rotates the guard on its own, so a bey launched in High Mode drops into Low Mode mid-battle as a consequence of hitting the rail. That is the design intent — a taller, more forgiving stance at launch that converts into a lower, faster one at the moment of the dash.
Whether that conversion is worth having is unsettled. The documented behaviour cuts both ways. Launching in High Mode is what most analysis recommends, because it produces the smoother transition, but the taller stance carries more burst risk, and the narrow tip raises knockout risk once it drops. Launching in Low Mode invites a worse failure: the guard can jam against the wider part of the ratchet, leaving the transition stuck and producing either skipped rail contact or a violently fast dash that throws the bey out on its own.
Plain Kick is still the recommendation for players who want predictable results, and Trans Kick has not displaced it. Treat it as an experiment worth owning rather than a solved part.