Push buttons compress to control connected circuits and are intuitive to use, making them ideal for use as emergency stop buttons. Also known as push-button controls, they come with contact blocks or require compatible contact blocks to complete their assembly. Push-button assemblies with contact blocks are ready to install and provide control of one circuit. Push-button assemblies without contact blocks provide control of one circuit. Multihead push-button assemblies with contact blocks are ready to install and have two or more operator heads to control multiple circuits. Multihead push-button operators without contact blocks have two or more operator heads and provide control of multiple circuits. Hazardous-location push buttons with contact blocks are ready to install and provide control of circuits in environments where flammable gases, liquids, particles, and other combustible materials are present. Hazardous-location push buttons without contact blocks are for environments where flammable gases, liquids, particles, and other combustible materials are present. Wireless push buttons and transmitters control circuits remotely.