The Dogtra 3502X is designed for advanced handlers, packaged with a professional grade DUAL DIAL transmitter and IPX9K waterproof receiver. Geared towards professionals, the unique and essential features are intended to elevate your training regimen: 1.5-mile range*, Correction Level Lock, single-button Nick/Constant correction, HPP vibration, audible tone, 8-level Selector Dial, and expandable DUAL DIAL for independent 2-dog control. The DUAL DIAL transmitter comes with a dimmable OLED screen and two sets of the Selector Dial and buttons dedicated to each collar, which allows seamless and effective operation of the collars without switching levels back and forth. * The range may reduce depending on the surroundings.