This Coaster is 4 x 4 and has a beautiful gloss finish. Customize this Coaster for YOUR FAVORITE TEACHER. It is approximately 1/8" thick with rounded corners and come in two options; a nonslip rubber back or a sturdy Hard Back (see Pictures). They will be customized with the name of your choice. The design will be fused into the surface of the coaster making it indestructible. The photo will NOT FADE, PEEL OR CHANGE IN ANY WAY... it will last a lifetime!!! The Hard Back coaster is available with rubber feet preventing it from slipping on any surface. In 'Notes to Seller' at checkout, please provide the name you'd on the coaster and I will create a lasting gift for your special someone. I look forward to creating something unique and special for you. Thank you for visiting my Store!!