T-Duo Seals has a very unique and specific design where the seal itself acts as the Piston of the cylinder. T-Duo seals are double acting seals which forms the piston by having the seal covering the piston. They are used in both Hydraulic and Pneumatic Cylinders where it is screwed or attached it to the rod of the cylinder. T-Duo has its name from the “T” cross section it has in the profile.