1100% WATERPROOF & EASY TO SYNC - YOUTHINK dog training collar receiver is upgrade version,enhance the deep water resistance again,suitable for dog training in water under 1M. Especially for swimming and beach; Press the red button of collar receiver for 24 MODES (SHOCK, VIBRATION, LED LIGHT AND BEEP MODE) - 100 levels of shock and vibration by use of up & down button. Use a beep tone mode give an audible warning. Led light mode is design for night training. Four mode meet your different training needs. T 3POWER SAVING DESIGN & 300 METERS REMOTE CONTROL- The controller enters sleep mode after 20s of no operation,and wakes up by pressing mode for 1s. Charge the controller at least 6 hrs for the first time. The receiver is the same; Remote training collar is 4ONE CONTROLLER TRAININGING 1 OR 2 DOGS - Use the same controller to train 2 dogs at the same time,additional receiver collar need to buy separately. Only by training, the dog can understand the intention of its owner,effectively correct barking, aggressi 5APPLIES ALL DOGS & EASY TO CARRY -Collar size from 7 to 26 inches. 2 set of different lengths metal probes,according to dog size and fur length to choose proper set. There is a hook on back of the controller,convenient to hang on the waist to carry at an