Our pet training collar receiver is compatible with our dog fencing system. When your dog approaches the boundary, the signal causes the dog’s collar receiver to deliver a warning beep first. If your dog continues closer to the boundary, the collar will issue a mild shock. If your dog continues further, the collar will issue stronger shocks until your dog returns to within the boundary you have set up. Your dog will naturally seek to avoid correction, and is content staying within established boundaries. Keep safe in limited space. (Only Collar, Fencing System Not Included) 2 Training Modes: This dog training collar features beep and shock modes which can receive the remote signal sent by the remote transmitter(Not Included) and will beep or shock accordingly, which can effectively train him back to the play area you set. (Note: The Transmitter Is Not Included) Adjustable Collar: With an adjustable neck circumference of 7.5in-17.92in, it’s suitable for small, medium, and large dogs between weighing 4lbs . High-Sensitive Signal Receiver: Built-in high-sensitive chip, our dog training collar receiver can receive the remote controlling signals up to 1.2 acres/53189Square FT area. (Can Be Adjusted On The Transmitter) Outdoor Usages: This wireless collar can be handy if you’re teaching your dog off-leash commands in the park, backyard, or anywhere else. Long Battery Life: This collar can be used for about 10 days with included 4LR44 6V battery for daily use. No need to change it frequently. Note: Our dog training collar receiver should be used with the accordant dog fencing system GPCT2529 in our store. Brand: iMounTEK Product Type: Electric Dog Collar Receiver Color: Black Material: ABS Battery Type: 4LR44 6V(Battery Not Included) Runtime: 10 Days Fit For Dogs: Fits Dogs 4lbs with Neck Sizes From 7.5in To 17.92in Collar Strap Length: 45.5cm/17.92in Item Size: 6.5x3.5x3cm/2.56x1.38x1.19in Item Weight: 56.5g/0.12lbs Package Size: 11*11*4.5cm/4.33*4.33*1.77in Package Weight: 95g/0.21 lbs 1 x Training Collar Receiver