The super popular ½ mile Mini Educator ET-300 is called the “Mini” because of the smaller size remote transmitter. It’s by far their best seller & favorite among professional dog trainers because of its small size & versatility. It comes w/ a small, low-medium power receiver collar that is light & gentle enough for dogs as little as 5 pounds w/ soft temperaments, but powerful enough for larger, harder dogs, too. Featuring vibration & tone only modes & 100 levels of medical grade static stimulation (similar to a TENS machine) allows you to fine-tune the collar to your dog's exact temperament &, the Lock & Set feature allows you to save that setting directly into the remote. As with all of their stopwatch-style remote transmitters, it's ergonomically designed w/ buttons right at your fingertips so that you'll never have to take your eyes off your dog during off-leash training. Low battery indicators on both receiver collar & remote transmitter w/ 2-hour rapid charge LiPo batteries. The waterproof design on the Mini Educator e collar ensures that your receiver collar & floating remote will continue to work even if submerged in water. Don't settle for less when it comes to your dog's training needs. Trust in Educator - the brand recommended by professionals - & experience unparalleled results w/ the ET-300 Mini E-Collar today! Fits neck size approximately 8 1/2”-25” (we cut the excess off as this was too long for my girl). Collar & Transmitter has some light staining.