This version has a pressure limiter Fits universal hose connections Connection into caravan/motor home system takes 12mm pipe and is push fit for easy connection – if you need to use 15mm pipe then you will need a Whale WX1509B Stem Adaptor and WX1504(B) Equal Straight to make the conversion Dual usage: water fill up from mains supply and from an external tank with an external submersible pump. It is not suitable for systems which draw water in using an internal pump inside the caravan, motor home or building. Simple installation – you will need a 60mm dia cutter Care must be taken not to create a pressured system during installation and filling, damage to the water storage tank may result. If unsure please consult a local installer. The tank needs to be vented or the taps turned on during filling. The water point does allow air to be sucked into the system when water is being used.