This mod adds five trailers to the game. You can find them in the regular trailer dealer: select the lowloader model and in the chassis section and scroll down untill you find them.
°Lowloader 5 axles
°Lowloader 6 axles (2+4)
°Lowloader 6 axles (3+3)
°Lowloader 2 axles (2x8)
°Lowloader 4 axles (4x16)