There are now two different looks to this same transmitter model. Both function identically. CONTENTS The Stinger transmitter is a very small (1-5/8" x 3" x 1/2") visor style, TRI-DIP (+, 0 & -) remote operating at 318 MHz. The Stinger achieves its small size by using state-of-the-art, surface mount components. It has been designed for use with the Allstar 9 dip switch systems. CODING Access to the Stinger's toggle code switch is achieved by sliding down the front cover. Set the NINE-digit toggle code switch to match the code set in the receiver. Move switches using a small pointed object, such as a paper clip. Gently switch the small switches to either + or - positions. When complete slide front cover back into position OPERATION Once the codes are set to match the transmitter codes, you may test the system. Ensure the gate or door is visible and clear before testing. Step 1- Push the Stinger's button from a distance of about ten feet. If the receiver activates, the switches are properly set. Step 2- Test the transmitter from several locations to discover any "blind spots" caused by interference. BATTERY ACCESS Slide front cover down to reach battery compartment. Be aware of battery polarity when replacing the A23 battery. TECHNICAL SPECIFICATIONS Operating Frequency-318 MHz Number of Buttons-1 Battery-1 ea. 12V A23 Number Combinations- Lots :-) Operating Temperature- -20F - 100F Overall Dimensions-1/2" x 3" x 1-5/8" Weight-1 oz. COMPATIBLE REMOTES Allstar 9931, Allstar 9931T, Allstar 9931mt, Heddolf P220