What sort of shower waste is required for this tray?

[JackyBailey]

Hi,

Just looking for some advice as seen a few different things online. I'm installing a shower tray in our bathroom but this one has a square inlay to it first. Is this just a standard wet room square plate and then a normal shower trap underneath? I have seen some mcalpine ones but they are £70+

Any help would be very much apricated

 

[fowlerboi]

It looks like a normal 90mm shower waste goes in there and then a square grill goes over the top instead of the chrome dome.

In other words it will probably be a special waste

alternatively you could use a normal 90mm waste and just have the square part exposed