＞Have 8 function keys.
＞Control contact is up to 8.
＞With battery voltage warning device, the power supply is cut off during low power.
＞Program the button function by computer software.
＞Up/down, east/west, south/north can be programmed to interlock or non-interlock, toggle or normal etc.
＞Start button can be program to be start, normal, toggle function