The be quiet! System Power 11 550W is a reliable power supply designed for stable energy delivery in home or office computers. It features an 80 PLUS Bronze certification, reaching a maximum efficiency of 89.7% at half load, which helps reduce energy waste. The unit utilizes a double forward topology with DC-DC conversion to ensure steady voltage across its rails, including a single +12V rail capable of delivering 45.83 A. To keep the system quiet, it uses a silence-optimized 120mm fan with a rifle bearing, maintaining noise levels as low as 10.4 dBA under light loads. The black chassis measures 150 x 140 x 86 mm and weighs 1.92 kg, fitting standard ATX 3.1 form factors. Its non-modular cable set includes a sleeved motherboard cable and flat cables for PCIe and drives, with a maximum length of 55 cm to keep your internal wiring tidy. This model is well-suited for users building a balanced PC, as it includes modern connectivity like the 12V-2x6 connector for newer graphics cards alongside traditional SATA and PATA ports. Safety is handled by a comprehensive suite of protections, including OVP, UVP, and SCP, ensuring your components remain safe during unexpected power fluctuations.