... output or NPN / PNP output 2.With or without controller 3.Resolution available for 20,30,40,80mm 1.Features ... 20mm, 40mm and 80mm.* Composed of separate emitter, receiver(reflector), controller, cable connector and installation bracket.* Fast response <20ms.* LED indicator ... contact us ! IBEST ELECTRICAL CO LTD ! IBEST With Inside Controller , SNA Series 1240mm Protection Height Safety Light Curtain