The GSR6-27.5 series environmentally friendly gas-insulated metal-enclosed switchgear (C-GIS), independently developed by our company, is a high-performance, high-quality, next-generation green and environmentally friendly medium-voltage switchgear for railway applications. It utilizes dry air (D-air) as the insulating medium and integrates vacuum arc-extinguishing technology, APG solid sealing technology, gas insulation technology, and interface insulation technology. The product has passed type testing verification and new product technical appraisal by national authoritative testing institutions, securing multiple national invention patents and utility model patents with independent intellectual property rights. The product is primarily designed for single-phase or dual-phase electrified railway systems with a rated voltage of 27.5kV and a maximum voltage of 31.5kV, such as high-speed railways and passenger-dedicated lines.