Rail-mounted device for installation on DIN-EN 60715 TH35 mounting rails. 4 division units = 72 mm wide. The modular combined surge protector reliably protects electrical systems from transient overvoltages. It combines lightning current and surge protection in one device. Ideal for TN/TT networks with increased protection requirements. The design, simple rail mounting, and modular structure allow for quick installation and maintenance. It combines protection classes Type 1 and Type 2 in one device, providing reliable protection against the effects of direct lightning strikes as well as transient overvoltages throughout the building. According to DIN VDE 0100-443/534, the use of a MUA-30 is mandatory when, for example, the cable length between the main distribution and sub-distribution exceeds 10 meters. In the presence of external lightning protection, a protection level is required: Type 1 in the main distribution (e.g., MUA-100, MUA-50) and Type 2 in the sub-distribution (e.g., MUA-30, MUA-20). A Type 2 surge protector in the sub-distribution is only required if the cable length to the main distribution with installed Type 1+2+3 exceeds 10 meters.