That’s a Fuel Dispenser Nozzle / Petrol Pump Nozzle
What it’s used for:
Filling vehicles, generators, tanks, or jerrycans with fuel at a petrol station or private depot.
From your pic:
1. Type: Automatic shut-off nozzle. The red body is usually for Petrol/PMS. Black handle with trigger + latch.
2. Spout: Long aluminum spout goes into the vehicle tank. The corrugated section is the vapor recovery area on some models.
3. Function: Squeeze the trigger to start flow. The latch lets you lock it open so you don’t have to keep holding it. It auto-shuts off when the tank is full to prevent overflow/spillage.