E-Collar K9-400 Canine Handler 3/4 Mile Remote TrainerThe K9 400 K9 Handler is a 3 4 mile range trainer loaded with unique features, making it the most humane and effective remote control K9 trainer available. Although small in size (2x1. 5x1 & 2. 4 ounces) and the worlds smallest rechargeable k9 collar, it provides plenty of stimulation for most dogs. The K9 Handler has a unique COS (control of stimulation) technology that provides very clean stimulation without the normal head jerking often found with