The TTS/L-AI is the TTS/L rod seal, a semi-compact profile with an extra lip, in the AI version. On the type B seals in this range, AI stands for an anti-extrusion ring on the rod side; check on the old seal whether yours has that ring.
There are 21 sizes, from 25x33x5.8 to 110x130x11.5, given as rod × outside diameter × height. Measure the rod and the groove before choosing.
Also check that the groove in your cylinder was made for this version.