All forms are measured in inches.This Wallie Form has a 2 depth to create a deep casserole dish. It also includesLifting Groovesso you can easily remove the Form from the clay. There is a center hole for a Spacer if you want to elevate the Form while constructing the piece, adding a Spacer will also help make your dish even deeper.**Spacer PullNOT included (sold separately).The forms are wood so to make them last for thousands of uses make sure you let them dry in between each use. The timing of making them and removing the form from the slab is very similar to plaster. If left on too long your clay will crack, the wood will mold or start to get soft. Mold can easily be washed off with dish soap and if edges get rough you can use sand paper to smooth them.