2 Channels Maximum Control & 2 Receivers Set : If you want to train two dogs through one remote, PATPET can meet your needs. Longer remote control distance allows you to train your pet easily both indoors and outdoors 3 Training Modes & Security Switch : provides 3 Safe effective humane training modes. Customized static shock (1-16) levels, vibration (1-8) levels, standard “Tone” mode. Suitable for your different needs in different scenarios Comfortable for All Sizes of Dogs : The adjustable nylon collar fits dogs with neck sizes 9" - 24". Stronger and smaller collar, Perfect for all size dogs (8 lbs~120 lbs). Receiver size 2.3(L)*1.4(W)*1(H) inch, even puppies fit perfectly IPX7 Waterproof Technology : If your dog likes to play with water? Don't worry, The IPX7 waterproof collar stays in a water depth of 3.2 Ft for half an hour, and its performance is not affected. So your dog can enjoy chasing toys around a pool, or playing in the rain freely 2 Hour Quick Charge & Longer Battery Life : After 2-hour fully charging, the receiver collar is able to work 30 days and the remote is able to work 60 days. Low battery display on both remote reminds you charging time in advance