Two new enhancements have been made to several series of the firm's safety switches to widened their application flexibility. The enhancements include the Dual-Entry Head for GK and GKR/GKL Series of key-operated interlock switches and the Positive-Opening Four-Circuit Direct-Acting Contact Block. The Dual-Entry Head increases the interlock switches' application flexibility by providing both side and top key entry. Also, the new operating head provides greater resistance to tampering, it's claimed. GK and GKR/GKL switches with Dual-Entry Head offer solutions to improve operator safety on the automotive factory floor, machine tool, material handling, and packaging industries. The switches are intended for use on protective guards, such as hinged or sliding doors, screens, and protective covers and enclosures to prevent access to hazardous machine motion.