Device designed for lab works study of torsion of couples and torsion pendulum.The constructional details are given below:A plate with central hole equipped with two pulleys with ball bearing. Lines traced on plate give the direction of action lines. A dented lever with central core allows hanging torsion line. A hanger bracket holding a graduated drum on which axis the torsion line is fixed. A set of 7 torsion lines with tips. Six round weights and two plates (weights: 10x2g) to apply forces to lever are provided.