A trolley 100 for a rail 10 is described. The trolley 100 comprises a frame 110, a set S of wheels 120, including a first wheel 120A and a second wheel 120B, rotatably coupled to the frame 110 and an attachment member 130, coupled to the frame 110, for suspension of a load W therefrom, in use. The first wheel 120A is rotatable in a first plane P1 about a first axis A1 and the second wheel 120B is rotatable in a second plane P2 about a second axis A2. The first plane P1 and the second plane P2 define a line L. The trolley 100 is arrangeable in a first configuration, wherein the attachment member 130 is arranged at a first angular displacement D1 about the line L. The trolley 100 is arrangeable in a second configuration, wherein the attachment member 130 is arranged at a second angular displacement D2 about the line L, wherein the first angular displacement D1 and the second angular displacement D2 are different. A rail assembly 1, including the trolley 100 and the rail 10, is also described.