Mighty Paw Martingale Dog Collar 2.0 Trainer Approved Limited Slip CollarOur Martingale Collar 2. 0 is one of our dog training collars and very easy and safe to use on a large variety of different size dogs. It works great for teaching polite leash walking & heeling skills and prevents moderate to average pulling. You can also control your dog's leash reactivity with it, especially when you combine it with one of our signature dual handle leashes. For example, our dual handle bungee leash. That's my personal favorite