Through-beam Sensors have separate emitters and receivers to enable setting them at the required distance.
There are 2 products of Through-beam.
Long-distance Through-beam Photomicrosensor
EE-SPW311 / 411
Through-beam Photomicrosensor with a sensing distance as long as 1 m.
Photomicrosensor with Amplifier and Cable
EE-SPW321 / 421
Compact, Thin-profile Photomicrosensor with special amplifier.