The Omron F3SG-4SRA0920-85 is a Type 4 safety light curtain from the F3SG-SR series, built for point-of-operation guarding where a 85 mm detection capability is sufficient — think hand or torso detection, not finger. The 920 mm protective height covers a typical standing-operator zone, and the 12 beams at 80 mm pitch give you a clean rectangular field. Operating range spans 0.3 m to 20.0 m, so it handles both tight machine access and longer aisle coverage without a separate lens set. Supply is 24 VDC straight into the body; no separate controller brick needed for basic muting and blanking — those functions are built in. The IP65/IP67/IP67G rating means it sheds coolant spray and washdown, and the G suffix adds oil resistance for machining environments where cutting fluid is airborne.
The 85 mm detection capability is the headline number: it catches a 85 mm diameter object anywhere in the field. That is larger than a hand (typically 30–40 mm minimum), so this curtain is sized for torso or limb detection — not for finger proximity. If your risk assessment calls for hand detection, you need a finer pitch (14 mm or 20 mm). The 80 mm beam pitch and 12 beams are the mechanical enablers behind that capability. Protective height of 920 mm is the actual guarded zone from the first beam to the last. That covers a typical standing operator's reach zone up to about waist height. For taller openings, you stack multiple units or move to a longer body in the same series. The 0.3 m minimum range means you can mount it close to the hazard — no dead zone that forces a wider safety distance. Temperature range of -30°C to 55°C covers unheated warehouses and most factory floors. The IP67G rating is the differentiator here: the G stands for oil-resistant seals, which matters on transfer lines and machining centers where standard IP67 curtains fail from seal swelling.
The F3SG-SR series is a mature platform with broad installed base, so replacement units match existing mounting brackets and cabling. If you are filling a BOM line for a panel that already uses F3SG-SR bodies, this drops in without adapter plates.