Lap vent exhaust?

[bhm1712]

Do these do what they say on the tin? Or snake oil?

DIY fit roof vent for bathroom extract fan

BUY a DIY fit roof vent to use with your bathroom extract fan. Fitted from inside the the loft space. No scaffolding, external work or access needed.

lapventsales.co.uk

 

[noseall]

Do these do what they say on the tin? Or snake oil?

DIY fit roof vent for bathroom extract fan

BUY a DIY fit roof vent to use with your bathroom extract fan. Fitted from inside the the loft space. No scaffolding, external work or access needed.

lapventsales.co.uk

Does it sit in place of a tile?
I can't work it out. If it does replace a tile, choose carefully.

 

[bhm1712]

Does it sit in place of a tile?
I can't work it out. If it does replace a tile, choose carefully.

No, they allege it sits under the tiles but above the membrane or bitch felt and so vents out through the gap between the tiles, membrane and wooden slats (a few piccies attached from the website)