These Galvanised covers, come with a square insert which simply lifts out.

The following sizes are available:

Round (with insert)	60cm Diameter
Round (with insert)	90cm Diameter
Square (with insert)	60cm x 60cm
Square (with insert)	80cm x 80cm
Square (with insert)	100cm x 100cm
Square (with insert)	140cm x 140cm