This is a simple push-fit green polypropylene cap that slips onto the top of 2″ BSP male threaded vent pipes and then secured with two screws.
Atkinson Equipment
New
2" BSP
Atkinson Locking Vent Cap
Dry Break Coupling DBC-1000-AB
Aluminum Filler Cap Lugged, Aluminium Filler Cap for heating oil or fuel tanks 2″ BSP Female threaded, with NBR Sealing Disc