Product pictures
The tree grate is made of solid cast-iron. Both the tree grate and the innerside of the tree grate are round of shape. The grate is standard black waxed. This layer is going to oxidate within some months, therefore the colour is getting darker. 
Deviating sizes
TypeOuter sizeInside dimension
Samber 120Ø 120Ø 50
Samber 150Ø 150Ø 60
Samber 180Ø 180Ø 70
Samber 300Ø 300Ø 150
cast iron (black waxed)