Most collars have a D-ring because that’s where you clip the lead. An e-collar strap is built differently. It exists for one reason only: to hold the receiver unit snug and stable against the dog’s neck so the contact points stay consistent.

Choosing the right strap for your e-collar can make a massive difference to comfort, contact quality, and training success. Two materials dominate the market: Biothane and Bungee

Flex Collars. Correct E-collar Position on the Dog's Neck. Barry demonstrates how to wear FlexCollars strap (in Green Camo)