LELK1-1REC4-27129-939 is a single-pole hydraulic magnetic circuit protector from the LEL series designed for low-cost power switching, reliable circuit protection, and accurate circuit control in international applications. The unit features a series internal configuration with 1REC4 auxiliary switch capability, supporting both vertical and horizontal mounting orientations with rocker handle operation. It is rated for 27.129 amps at the specified voltage and frequency configuration, with VDE approval to VDE 0660 part 101 standards. The protector offers multiple delay options (short delay, long delay, motor start, and instant trip) and is available with various terminal types including screw, clip, and bullet terminals. This device is commonly used in industrial equipment, power distribution systems, and applications requiring both overload and short-circuit protection with precise trip characteristics.