The Pet Life ®  Nano-Bark Mini LED 1-to-2 Dog 2,000 Foot Range 8-Level Vibration and Tone 32-Level Stimulation Training Dog Collar operates at a whopping distance of approximately 600 Meters and is 2 Channel or can control upto 2 dogs (additional receiver sold seperately). The Nano-Bark offers 3 Operating Modes that consists of 8-Levels of Sound and Vibration with 32-Levels of Electronic Stimulation which the user has the option of custimzing and all controlled by a single button located on the transmitter . The Nano-Bark is small yet powerful with an LED screen that displays Battery-life, Operating Mode, Intensity Levels and Channel identifier with a built-in safety keypad lock that prevents accidental usage. This device features an IP67 Waterproof rating and includes a Dual-USB Charger that simultaniously fully charges both the Receiver and Transmitter in 2 Hours time for an approximate runtime of 20 days for the receiver and 40 days for the transmitter. Additionally, the Nano-Bark is equipped with 4 Contact Points and covers for Long and Short Hair dogs with an included wrist rope for convenient carrying and a durable dog collar that fits all neck-girths ranging from 6.5 - 24 Inches. 

Specifications: 
Battery Capacity: 300mAh 
Charging Port: USB
Charging Time: 2 Hours
Standby Time: Receiver: 20 Days | Transmitter: 40 Days 
Battery Type: Polymer Lithium Ion
Rated Input: 5V/1A
Operating Voltage: 3.7V
Waterproof Rating: IP67
Range: 670 Yards / 600 Meters