It has a depth of approximately NUMBER@1 inches -LRB- NUMBER@2 cm -RRB- on the sides and NUMBER@3 inches -LRB- NUMBER@4 cm -RRB- in the center .

It is about NUMBER@1 inches -LRB- NUMBER@2 cm -RRB- deep on the sides and NUMBER@3 inches -LRB- NUMBER@4 cm -RRB- deep in the middle .
