This was a piece of Stainless Steel mesh which I was gifted for hobby project some decades ago, which I then cut to the shape required. - however, the project fell by the wayside.
The main circular part is 32 cm diameter and the mesh hole (or wire separation) is 0.75 mm.
(It seems a shame to send it to the tip !)
Lymm WA13
Stainless Steel Mesh (Lymm WA13)
This offer has been gifted to someone and is no longer available.