The Omron E32-T24 5M is a sleeved through-beam fiber optic sensor head with a 5 m standard cable, designed to detect small objects (5 μm minimum) away from the amplifier base.
The 5 m cable length gives you standoff from the amplifier, while the through-beam sensing pair detects objects as small as 5 μm diameter. The sleeved construction (15 + 15 mm head length, 1 + 2 mm diameters) lets you route the fiber through tight spaces; bending radius is R10. Cable is listed as standard type and cut to length, meaning you can trim it to fit the exact run without affecting performance.