An optical repeater is provided for use in an optical communication network wherein only wavelength ranges having desirable gain characteristics are used for communication. The multi-layered carbon-based hardmask includes at least top and bottom carbon-based hardmask layers having different refractive indexes. The weight member is securely mounted in the recession of the golf club head body by a welding procedure that uses a welding material. They are granulatable, with the granules produced thereby having non-tacky surfaces at room temperature and being capable of being readily processed into molded objects by injection molding processes. The switch detection device is incorporated to a turning operation mechanism which includes a lever lock assembly, a deadbolt lock assembly, a window sash lock assembly, an odometer wheel, a hinge provided with a first hinge member and a second hinge member interconnected by a central axle, a door closer, a water faucet, a rotatable switch, or a rotatable lock. The proximal end of the body may optionally form a finger grip.