The first value of the bins is the depth and the second is the height.
Ex. A 35x30cm box will be made with a depth of 35cm and a height of 30cm , see the Image to find out more.
Inspection box from below
measuring 25x25cm - internal space 19x22cm --- about 19cm thickness and about 22cm in height
measuring 30x25cm - internal space 19x27cm --- about 19cm thick and about 27cm in height
measuring 30x30cm - internal space 24x27cm --- about 24cm thick and about 27cm in height
measuring 35x30cm - internal space 24x32cm --- about 24cm thick and about 32cm in height
Front inspection box
measuring 25x25cm - internal space 19x19cm --- about 19cm thick and about 19cm in height
measuring 30x25cm - internal space 19x24cm --- about 19cm thick and about 24cm in height
measuring 30x30cm - internal space 24x24cm --- about 24cm of thickness and about 24cm in height
measures 35x30cm - internal space 24x32cm --- about 24cm thick and about 32cm in height
The overall diameters of the shutters are shown here Link