The Telemecanique XUM8APXBL2 is a tubular background rejection photoelectric sensor — the kind that sits on a conveyor line and sees the part but not the shiny metal behind it. Background rejection means it's forgiving on dusty, mixed-surface setups where a standard diffuse would false-trip.
It's a tubular form factor, common for photoelectric sensors in food, packaging, and material handling. The background rejection means you can aim it at a belt or a metal chute and it'll still only pick up the product — not the belt's shine or the chute's reflection.