Our dog martingale collars are very thick and strong compared to a lot of other collars on the market. Our collars, like everything on our site are hand sewn. While we do try and make them all identical, please keep in mind that they are all individually made by hand if there are any mild inconsistencies in the stitching or exact size. If you are unsatisfied, please reach out and we will be happy to help resolve the issue. 
Sizes and rough measurements are listed below (neck size);
X-Small: 9”-12”
Small: 11”-15”
Medium: 15”-21”
Large: 18”-26”
X-Large: 23”-31”
Width of collars are roughly 3/4”-1”