The mechanics of the safety collar allow it to be much more flexible than a standard buckle collar. The two strap ends can move 90-degrees away from each other. If you attach a leash to this ring, you'll find that it often assumed this shape as soon as the dog puts any pressure on the leash.
The ring also offers a convenient pivot point that allows the collar to flip over and basically roll off your dog's head. The greater flexibility and ability to roll means this collar is much easier for your dog to back out of if they get stuck on a fence wire or tree branch. That's important if your dog is running around in heavy brush. For that reason, a safety collar is usually fitted loosely enough to slip over the dog's head.
Aside from the safety aspect, these collars are also super convenient because they place the center ring right at the back of your dog's neck. Most safety collars also have a D-ring next to the buckle. Attach tags to this ring and they'll act as a counterweight, keeping the center ring right at the top all the time.
This type of escapeable collar is much less prone to getting lost than our KeepSafe breakaway collar. It's not going to just fall off.