Says vivasanitary.co.uk and then you visit that and look through their product list!
Even if you do have to scroll past PB Plumber's ugly mug to get there!
What is your purpose doing this?
If you have poor flow and pressure from the supplier, then upgrading your 15 won't make much difference.
Ask supplier to check your flow and pressure at their stopcock and compare it against measurements at your stopcock.
Is your flush pipe at a skewed angle going into the pan?
Is it under any stress?
To stop it leaking, I'd be adding plumbers mait to the ribs of the flush cone.
Or maybe silicone.
A plumbers job is to make things connect together and be leak free... This is where experience and tricks of...
I've said this on here before...
They shift the onus of flushing onto the installer! Shifts the cost elsewhere, so they can sell them cheaper.
Not easy taking brand new rads outside to flush through with a hose, before fitting! Especially if you've 10 of them to do!
Some are absolutely full...
You can try!
Pull the fixing up as you tighten it down to the pan.
It relies on that sliding bar to contact the nut and hold it trapped whilst the bolt screws down through it.
When the fixing is very near to the pan, there should be enough of a grip on it to fully tighten.