Features: Frequency: 18 kHz. Fuse Type: 250 volt 1/2 amp - inside transmitter. For use with the PIF-300 Wireless Containment System. On-off switch, high-low switch, and boundary control dial. The shape of the signal is in a perfect circle and the shape cannot be altered. Range of the Instant Fence can be increased by using two or more transmitters. Signal field can be adjusted anywhere from a 15 to 90 foot radius from the transmitter. Signal is cancelled where the circles intersect, allowing the pet access to the entire area. Use multiple transmitters to create overlaping containment areas allowing your dog greater mobility.