Designed for the Dogtra PL and QL bird launchers but is compatible with most after-market bird/bumper launcher systems. It uses an advanced 2 port system so you can run two launchers off one receiver with a dual sound attention getter that uses a realistic duck call for retriever training marked retrieves and the beep sound for locating the launcher in heavy cover during upland work. A maximum of 16 launchers can be operated off a single transmitter at a range of one mile. It is a water-resistant transmitter and receiver with user friendly coding means you can add extra receivers and match them anytime, anywhere. Plus, it has a multi colored LED light battery life indicator and uses a long lasting rechargeable Ni-MH batteries.