Educator Quick Snap Bungee Dog Collar, Biothane, Waterproof, Odorproof, Easy Connect and Disconnect Clasp and D Ring with Comfort Bungee Loop, Adjustable for Custom Fit, 3/4-Inch, Red3 4" wide collar fits all Educator 300, 400, 500 and 900 series training collar receivers; all other models require 1" wide collar 33 inch collar for small to medium dogs 10 lbs with neck diameter between 11. 7 " 24 "; Can be cut to custom length with scissors For extra small dogs 5 pounds or more, we recommend the 3 4" x 22" mini double bungee collar Premium Biothane material provides unmatched durability and won't fray, waterproof and odorless, easy