Abstract: An accessory assembly (1) of toothed belts (9), toothed conveyor belts (9a) or portions thereof, comprising a base piece (2), a first piece (3) and a second piece (4) with respectively a first, a second and a fourth coupling part (21, 31, 41). The first and the second coupling part (21, 31) are complementary to one another so that the first piece (3) is couplable above the base piece (2) in one or more predetermined positions and the fourth and the first coupling part (41, 21) are complementary to one another so that the second piece (4) is couplable above the base piece (2) in one or more predetermined positions. The first piece (3) comprises a third coupling part (32) complementary to the fourth coupling part (41) and which faces in an opposite direction to the second coupling part (31).