A hyper-pressure water cannon, or pulse excavator, is able to discharge fluid pulses at extremely high velocities to fracture a rock face in excavation applications. The scale portion includes a display for registering the weight of the person standing thereon. An actuator or motor is disposed in the hand grip that is responsive to a control signal from a control system for dynamically controlling a force applied by the trigger to a user of the hand control interface. Filler is placed above the lower sections of the pocketed spring assembly. The sheet material wrap is so configured as to provide means by which the first opening of the enclosure cannot take place without the wrap being torn or partially or fully removed. One tooth of the units runner for moving on from 1 to 2 is a tooth of an auxiliary runner secured to the units runner and which is able to engage alternately with the teeth of the tens indicator runner and with a cam secured to the tens runner and intended to allow the auxiliary runner to drive said tens runner by one step between 31 and 01 without driving the units runner.