A circuit arrangement in which a further electronic component for connecting and amplifying an electrical voltage is arranged between a first series arm and a second series arm to achieve limiting of a voltage between a first clamping point and a second clamping point in the circuit arrangement. The annular band comprises at least one elastomeric material comprising at least one copolymer thermoplastic elastomer containing blocks of polystirene and polyisobutylene, and a polybutene oil. Preferably, the speed of operation of the tractor is accomplished through changing transmission speeds so that the PTO shaft speed is maintained at a substantially uniform rotational speed.