Large/L size: 135x92x21mm/5.31x3.62x0.83inch Medium/M size: 120x90x17mm/4.72x3.54x1.37x0.67inch Small/S size: 99x70x15mm/3.9x2.76x0.59inch (There is 2-3% difference according to manual measurement) Package Including( you choose ): 15 PCS C-Shape Transparent Clear/Blue Cheek Retractor Pls leave a note in your order if you want mix sizes or colors. You can use these spare to stop the need for washing them in between playing the game which is guaranteed to be a massive family hit Christmas/holiday/party.Good for both serious dental use and hilarious Mouth Opener Games like "Watch Ya Mouth", "Speak Out Games" and "Mouth Guard Challenge Games", etc. over 3 years old.