PRODUCT INFORMATION: SPECIFICATION: Color: black Size: 99.5*57MM Package included: 1 x Back Button Attachment INSTRUCTION: 1. Programming function setting: Press and hold the SET button for 2 seconds, the LED corresponding to X will flash quickly (4HZ), and then short press the M1 or M2 button, the LED lights will display slow flashes in sequence on the corresponding function silk screen (the lighting sequence is X, O , , , R3, L3, R2, L2, R1, L1), and then press the SET key, the corresponding function will be mapped to M1/2; for example: when entering the programming mode, press the M1 key, the LED will display Go to R1, and then press the SET button again, then the LED on R1 will become long bright, and the function of M1 will be R1; the programming of M2 is similar to the above. 10 LEDs are used as button function indicators to indicate the function of the programmed button, and a maximum of 2 LED lights can be displayed. 2. Cancel function: Press and hold the SET button for 5 seconds, the programming indicator LED will change from flashing to off, then the M1/2 function will be cleared, and the button has no programming function at this time. 3. Programming button memory function: insert the back button expander into the handle, if M1/2 has no function, LED1 will flash slowly (2HZ) for 3 seconds and then go out, and LED1 will flash quickly after long pressing the SET button to enter the programming mode; if M1/2 When the last programming function is memorized, the corresponding LED light will be on. The programming function before power off saves the memory; the last programming function is still retained when the handle is inserted again, and the factory default has no programming function. 4. Turbo function setting: Press and hold the function button and the Turbo button at the same time, then the function button has the Turbo burst function; press the above combination button again, the Turbo function of the button will be cancelled. If the Turbo function is set, after pressing the button, the LED corresponding to the function will flash quickly (4HZ). NOTE Please allow 2-3 cm difference due to manual measurement. Besides different computers display colors differently, the color of the actual item may vary slightly from the below images, thanks for your understanding(1 inch = 2.54 cm)