Straight Through Pigtail Hose 20" - UKPOL x W20

A W20 fitting is the term often used in the UK and EU leisure market for the M20 × 1.5 parallel (right-hand) thread that’s common on many modern “Euro” caravan and motorhome LPG regulators and pigtail hoses. You’ll find it on pigtails.

W20 Thread form and size: In the caravan and motorhome industry, suppliers refer to M20×1.5 as “W20”—so when you purchase a pigtail or T-piece labelled W20, it typically has a 20 mm diameter, 1.5 mm pitch, and a parallel right-hand thread. This has become the standard inlet for many “Euro” bulkhead regulators and automatic changeover valves.
Common applications: Pigtail assemblies and adapters are often sold as POL × W20 (cylinder side POL to regulator side W20).

A UK POL fitting is the classic propane cylinder connector you'll find in the UK, like on Calor or FloGas bottles. On UK propane cylinders, the valve outlet features a left-hand internal thread, and you connect a male POL nut or stem from the pigtail or regulator. You tighten it counter-clockwise (because of the left-hand thread), usually needing a spanner to get a solid metal-to-metal seal.

In LPG systems, the “pigtail” is the small flexible link between a bottle and the fixed pipework/regulator. It’s designed to cope with movement during cylinder change, vibration, and slight misalignment without stressing fittings.

“Straight‑through” means the hose is a plain pass‑through connection with no built‑in non‑return valve (NRV) / excess‑flow device in the pigtail itself. In other words, gas can flow through it in either direction (depending on what’s connected), unlike “NRV/Excess Flow” pigtails that incorporate one‑way or safety features.