Closed trolleys are an advanced system for safe and reliable power supply of cranes and mobile equipment. Their compact profile with integrated copper conductors ensures protection against contact and external influences, minimizing the risk of electric shock. Available in a variety of current capacities and pole configurations, the system is designed for high wear and corrosion resistance. High-quality collectors enable smooth and uninterrupted transmission of electrical energy, which ensures a high degree of operability of the powered appliance.