All types of collar are available in a 1 inch (25mm) width. All collars are handmade with love. For the martingales the D-rings are 4mm thick and welded for safety, all other hardware is cast or welded for strength. The collars are stitched repeatedly in the joins and either side of the D-ring with extra strength thread. The side release clips are made from acetal which is stronger than standard plastic clips, and curved to fit the contours of a dogs neck. They are all lined for your dogs comfort and branded with the Graphite Delight tag which is sewn in inobtrusively.