This part of ISO 20957 specifies additional safety requirements for strength training equipment in addition to the general safety requirements of ISO 20957-1. This part of ISO 20957 is applicable to stationary training equipment type strength training equipment with stack weight resistance or other means of resistance like weight discs, elastic cords, hydraulic, pneumatic and magnetic systems and springs (type 2) (hereinafter referred to as training equipment) with the classes S and H. Any attachments provided with the training equipment for the performance of additional exercises are subject to the requirements of ISO 20957-1.