MDOG2 Free Standing Pet Gate, 23.6 to 39.4-Inch by 20.1 by 21.6-Inch, Black Train up to 2 dogs from the same transmitter (purchase extra receiver to train up to 3 dogs) Fits neck size 11" to 23" Range up to 1000 yards (on open air) 99 Levels for each model Free combination among tone, vibration and stimulation