1. WEIGHT is one of the key characteristics, as it directly depends on effectiveness or "punching" properties of the device. At the same time, it depends on how quickly the Top will get tired. Extremes are bad in both cases. To do an effective stroke with a light device, the Top will have to apply force and act for too long, which leads to fatigue. At the same time, it could be hard to work with heavy device, especially for rather small people. Too light devices may not produce any effect on "experienced" masochists, while too heavy devices may injure in case of an inaccurate stroke. Naturally, it makes sense to compare devices of the same type.