The fixed slot width provides reliable opposed-mode sensing of objects as small as 0.3mm. “There’s no need to align opposed-mode emitter and receiver. The SLM emitter and receiver are in fixed arms of the housing. You just install it, using the molded-in-beam guides and integral mounting holes,” says Jeff Curtis, senior application engineer at the vendor. The SLM available slot widths of 10, 30, 50, 80, 120, and 220mm range in price from $119 to $139.