1.Fabrics: All adopt high tenacity waterproof fabrics. 2.Multilayer internal materials: They will try utmost to prevent harm caused by external force. Part of the materials of viewfinder adopt spring geometry to mitigate the power of collision. 3.Material: Purified cotton and antiwear nylon are chosen to fully protect the camera. 4.Dedicated hardware fittings: They are nice-looking and solid, which have been through tensile strength testing, and can afford more than 100 kilogram tensile force.