Balancing machines and related equipment as follows— a balancing machines, designed or modified for dental or other medical equipment, having all the following characteristics— i not capable of balancing rotors/assemblies having a mass greater than 3 kg; ii capable of balancing rotors/assemblies at speeds greater than 12 500 rpm; iii capable of correcting unbalance in two planes or more; and iv capable of balancing to a residual specific unbalance of 0,2 g × mm per kg of rotor mass; b indicator heads (sometimes known as balancing instrumentation) designed or modified for use with machines specified in paragraph (a).