12mm John Guest Inserts (Pack of 50)

If you’re working with 12mm semi-rigid pipe—especially in a camper van, motorhome, or boat—these John Guest inserts are absolutely essential. Far too many people skip this step, not realizing how important these little inserts are. Without them, the ends of your pipes can deform (especially with hot water runs), and that’s when leaks start—often when you least expect it.I’ve seen people try to save a few minutes and end up with endless headaches from leaks and water damage. With these inserts fitted, you actually reinforce the pipe ends and ensure a proper, watertight seal every time. If you want true peace of mind and a leak-free system, don’t even consider running semi-rigid pipe without them. I’m a repeat buyer for a reason—they’re a small detail that makes all the difference. Highly recommended!

Fit great

Did the job purchased for with ease

I use these on the ends of 12mm push fit pipes for both hot and cold. They’re recommended for hot but they’re so cheap, why not use them for cold too ?Easy to fit and they resolve any issues where the pipe isn’t cut 100% straight.

Perfect for the job

Easy and simple foes what its supposed too

Perfect for my swift motorhome as when they built it (2019) they never fitted any either because of cost or never occurred to them? so as I always use inserts in my work role I would fit them , they are well made ,good fit and well packaged delivered next day very pleased and would recommend them 😀

Perfect for the hot water connections , keeps them locked in