The keeper strap will fit any of the muzzles, both the Birdwell and Don pare (except for the 114) and are designed to make it almost impossible for the dog to get the muzzle off.
They are adjustable from 32 to 47cm and are avialable in a variety of colours.
Please note they are designed to have the smooth side of the rivet head aganst the dog, and not facing outwards.
Please note if you just buy keeper straps the website triggers the small parcel postage rate but the actual postage cost is £2.20. We are working to fix the website, however in the meantime we will refund you the difference I.e £2.30