The movement at the heart of the RM 53-01 rests on two, braided steel cables just 0.27 mm in diameter. The tensioning of these cables is accomplished utilising 10 pulleys and 4 tensioners affixed to the peripheral baseplate and to each side of the main bridge. The cables run through the tackle pulley system and are attached to the tensioners on the other side. The watchmaker tensions the system by tightening a spline screw located at the centre of each tensioner. The pulleys ensure that the tension of the cable remains constant, and therefore that the system is balanced. Designed to sit suspended within the case, the calibre RM53-01 can withstand shocks exceeding 5,000 g’s.