The track of the towing vehicle, whether it be a tractor, quad or snowmobile, is wider than the track plate, and it is of course wider than that of a pre-stressed snow roller like BOroll. This is why unevenness in the terrain is transmitted to the track setter via the traction coupling. An undesired radial twist can occur lengthwise to the towing direction when the BOjoin component is not used.

BOjoin is designed flexibly as a universal joint, and therefore compensates for torsional forces better than a connection that is rigid. Compensation behaviour is supported and stabilized by four pins made of hard rubber on the double joints.

The coupling, say that of a snow cat, is held firmly with a rim washer, and the connection to the RamBO is held flexibly with a king pin.