What you receive :
 
1 Pair (2 pieces) of 4 MM thickness Acrylic Depth Guides - 250 mm X 300 mm 
Acrylic Depth Guides for Making Equally Thick Clay Slabs & resultantly professional earrings.
 
4 MM thickness is suggested for professional makers who create statement earrings.
 
3 MM thickness is ideal size for all general clay slabs.
 
Incase you are going to dome the earrings with resin top coat, 2 MM thickness would be the ideal size.
 
2 MM thickness would be best when you are rolling any clay components to be merged to your slab.