The rechargeable dog training shock collar for 2 dogs has 3 levels of shock and 1 level of vibration. This electronic dog training system can either shock 1 dog at a time or vibrate 2 dogs at the same time and has a range of 600 feet in ideal condition. Collar will work with dogs from 15 to 100 lbs. The set includes: 2 rechargeable receivers, 2 straps adjustable from 12 to 20 inches long, 1 wall charger, 2 sets of rubber prong and metal prongs, 2 test wires for the shock.