These adjustable things any good? or just look good?

[advicewelcom]

Hi, I put this adjustable joint into a WC waste that I was extending into the pantry...

But it seems to be leaking from the adjustable joints.

Just wondering if anyone had any experience with them and does or does not recommend them?

(Will be a pain in the a** to change it - but its going to under a new raised floor so better to do it now then later).

 

[snowhead]

FloPlast SP560B

Never used or even seen them, but the 2 collars on the middle section look like they may be designed to tighten the joint when set ??