The transmitter emits a harmless radio signal in a radius between 20ft to 850ft(selectable) around itself and the signal is detected by the collar. Besides, you can switch the transmitter to Dog Training Mode to train your dog via beep/vibration/shock modes.
eBay
Pets Wireless Electronic Fence Ip65 Waterproof Wear Resistant Rechargeable Remote Control Electronic Fence Pet Training Collar
Aliexpress UK
WIRELESS ELECTRIC FENCE- No buried wires anymore. It is easy to adjust settings for dog fencing system. TRAIN UP TO 3 DOGS & CONTAIN AS MANY DOGS AS YOU WANT- In wireless fence mode,collar works automatically when it is turned on; One transmitter supports multi-collars.
eBay
2 In 1 Electric Pet Wireless Fence Dog Training Collar Anti Runaway Up to 3 Dogs Outdoor Pet Containment Rechargeable System
Aliexpress UK
Boundary radius range: 1. Level: 40m/ 131ft; Level 2: 120m/ 394ft; Level 3: 160m/ 525ft; Level 4: 220m/ 722ft. -When installing you should put the transmitter high enough and open it wide enough to make sure that there is no barrier of fence debris between the transmitter and receiver (outdoor unobstructed use).
eBay
Solid Wood Splice Fence for Pets Indoor Separation Fence Transparent Dog Cage for Small Dogs Pet Fences Products Accessories
Aliexpress UK
【2 IN 1 WIRELESS DOG FENCE】: This 2-in-1 dog fencing system integrates the dog training device and the wireless electronic fence, operated simply. The range of the fence is defined as a circle (with selected radius) centered from the emitter.
eBay
500m Waterproof Wireless Dog Fence Containment System Electric Dog Training Collar Electronic Pet Fence Safety Pet Transmitter
Aliexpress UK
KPHR TEK dog fence system has a heavy-duty wire to establish an invisible boundary for dogs and sends a harmless signal from the transmitter to the collar receiver. If the dog gets close to the boundary-warning zone, it will emit a warning sound, while issue a mild shock if the dog continues moving closer to the boundary, the system will.
eBay
Pet Isolation Fence Dog Fence Mesh Fence Folding Breathable Mesh Fence Dog Safety Fence Entrance Pet Supplies Protection Fence
Aliexpress UK
Compared with traditional wireless dog fences, it has better stability and richer features. Your pet deserves it! If your dog want out of the safe area, the fence system will start stimulating automatically.
eBay
Indoor Dog Cage Small Dog Fence Indoor Enclosure Pet Fence Kennel Pet Fence Supplies Fences Dog House Enclosure Guard Rail
Aliexpress UK
【2500FT Remote and IPX7 Waterproof】 Super Far remote dog training collar range up to 2500 feet(875 yards), easily train your dog in the backyard, park. This dog shock collar with IPX7 waterproof function.
eBay
TP16 Pet Dog Electric Fence, Rechargeable Waterproof, 6 Level, Dog Wired Fence Containment, Pet Training Collar, Anti Run Away
Aliexpress UK
Maximum fence area：Adjustable to 480m. The electronic wireless fence dog trainer has a novel appearance and a comfortable feel. It is easy to operate and easy to switch between modes, which can allow pets to get better results within a limited range.
eBay
GPS Wireless Dog Fence, Electric Shock Vibrate , Range 100-3300 Ft, Adjustable Warning Strength, Rechargeable, Pet Containme
Aliexpress UK