Homeowners, this stainless steel turbine ventilator is a serious upgrade for your chimney! Made from robust 304 stainless steel that can handle temperatures up to 450°C, this thing is built to last. The hat design rotates with the wind - and get this, the more wind blows, the faster the blades spin, creating powerful air intake from inside out. What does that mean for you? It prevents exhaust gases from backing up, improves combustion, protects against rain, snow, wind, and even pesky birds trying to nest in your chimney. Super easy to install too - just grab a screwdriver and you're good to go. Important note: Make sure your chimney isn't more than 1 meter below your roof apex, otherwise any anti-downdraught cowl becomes less effective. Choose the 400mm size based on your smoke tube's outer diameter. It spins smoothly even in light winds, looks great on your roof, and works quietly without any annoying noise. Complete fixing kit included - just be careful during installation (gloves recommended to avoid scratches)!