Compressed air water draindown adapter for caravans/motorhomes etc. (Truma inlet fitting)

This device can be used to drain down the water system in a touring caravan (or other vehicle) fitted with a Truma water inlet. Along with a modified tyre valve and a couple of O rings it works in the same way as a commercial Floe device. Whereas the Floe is around 50GBP this costs less than 5GBP to create. (I can vouch for the original Floe as I had one with my previous caravan however it had a Whale fitting so was sold to someone else.)