Description: Approach to clearing old codes: Long press the two ( Lock & Unlock ) buttons to clear old codes(The LED indicator will flash once, which is the sign of cleared state). Approach to duplicating: Place them side by side(as close as possible), then press both one key of your old remote and the to-be- key on this remote simultaneously. The LED indicator will flash once. Learning process done. Other keys accordingly. Approach to recovering: Press the Start and Mute buttons for about 2 seconds till the light is on and flicker. (Or you can delete the codes and repeat the learning process.） Approach to test if the old codes are totally cleared: Press any key on the remote duplicator, if the LED indicator blinks instead of being on, codes cleared. Otherwise, undone. Humanized design: Button slide cover to protect buttons from accidental unplanned operation. Application: Vehicle central locking systems, garage doors, electronic doors, car sunroofs, heating systems, etc. Specification: Material: ABS plastic Working Voltage: DC12V Woring Current: 12mA Operating Frequency: 433MHz Control distance: 50m / 55 Yard (in empty areas) Overall Size: ( L x W x Dia. ): 56 x 30 x 14mm / 2.2 x 1.18 x 0.55 Inch Color: as shown in the display pictures Package Includes:(2 Pack) 1 Piece Cloning Remote Control