Murrelektronik optocouplers (from $16.50) are used to combine different signal levels or to isolate one signal from another. Optocouplers are similar to relay interfaces, providing an optoelectronic signal transfer between input and output. Optocouplers have a long life span and are suitable for applications with high switching frequencies, even over a long usage period. Murr slim interface relays (from $9.50) are highly compact, lightweight and especially useful when cabinet space is limited. Encased in a self-extinguishing plastic housing, these relays offer a long useful life, and are great for PLC automation systems, industrial machines and more. Murr multi-mode relay timers ($27.50) are for use in industrial installations and automation control systems. Features include 35mm DIN rail mount, slim 6.2 mm design and a green LED status indicator. Time ranges are from 0.1 to 300 seconds.