Radio Systems PIG00-10777 Elec Stubborn Dog Fence, In Ground Electric Stubborn Dog Fence, With Collar, For Pets 8 LB +, Comes With 500' Of Wire, Plus Flags, Can Expand To 10 Acres, Has 4 Levels Of Correction, Warning Tone With Pet Pager Vibration Ideal For Training Hearing Impaired Dogs, Tone Plus Vibration Only Mode For Training, Low Battery Indicator, For Replacement Battery Use #Pac00-12067, Can Expand To Multiple Pets, For Extra Collar &Use #Prf-275-19.