HT Sheet 70–87° (DN75)

The OK Lab Stuttgart project from Germany uses this kind of 75mm plumbing parts (common in mainland Europe) as the outer case for their DIY airrohr air pollution sensor - well specifically they use the Marley Silent HT Arc, but this is essentially the same thing from a different manufacturer. Note it the seal is very tight, so it took me a lot of physical pushing and twisting to connect two pipes together - for me it was the hardest part of assembling the sensor! It is a shame the postage to the UK is so high (£18 from Germany), but it works out OK if you're buying them as a group.