Eco fire isi mark fire delivery hose coupling 63 mm size stainless steel ss coupling material is stainless steel. A hose coupling is a type of fitting located on the end of the fire hose, which is typically made of steel, brass, or aluminum. The coupling has threading on each end, one female end and one male end, allowing the hose to connect with another hose, tap, or other water source. Very cost effective and easy to maintain, it is made with the best quality materials and goes through various levels of quality testing before reaching our customers. Our products go through numerous quality checks before it ships out to the customer thus ensuring the highest level of quality and performance.