The infrared source and detector in the photogate are permanently aligned in a rugged, machined phenolic housing.
The opening in the photogate between the source and the detector is 6.3cm wide by 5.9cm high. Each plug-in photogate has a 180cm cable and a stainless steel mounting arm (the tripod, post and clamp are not included, but may be purchased separately).
The photogate and timer are ordered separately, with either one or two gates per timer. The tripod, post and clamp shown in the darker photo are for demonstration purposes and are not included.