Size: 12,8 x 7 x 8,8 mm. These unit has two parts. The transmitter which sends the invisible light beam and the receiver. Whenever an object interrupts the beam, the unit activates whatever switches are connected to it, crossing gates, timer, relays, etc.

*** Photos may show additional scenery, structures, figures, vehicles, tools, etc which are not included. Please ask before ordering if you're unsure what's included. Most structures are kits which require assembly. ***