SAFE AND CUSTOMIZABLE: Create a customizable area for your pets to safely play UP TO 1/3 OF AN ACRE COVERAGE - expandable up to 25 acres with the purchase of additional wires and flags (sold separately) RECHARGEABLE, WATERPROOF RECEIVER COLLAR - quickly charges in 2-3 hours with each charge lasting up to 2 months depending on use. System is compatible with all PetSafe In-Ground Fence Receiver Collars, except for YardMax Rechargeable In-Ground Fence Receiver Collar ADJUSTABLE RECEIVER COLLAR - with 4 levels of static correction and tone, fits pets 5 pounds or more with neck sizes 6 to 26 inches ADD UNLIMITED PETS - with the purchase of compatible PetSafe In-Ground receiver collars (Excludes YardMax and UltraSmart) SURGE PROTECTOR - helps protect your transmitter from lightning strikes and powers surges U.S.-BASED CUSTOMER CARE: Our pet product experts are here to help you and your pet and are available by phone, email or chat if you have any questions QUALITY GUARANTEED: PetSafe brand has been a trusted global leader in pet behavior, containment and lifestyle innovations for nearly 30 years; we help keep your pet healthy, safe and happy