The Empire AXE 2.0 upper sensor board with trigger micro-switch (part #73232) is a replacement part that serves two primary functions: it houses the connection for the marker's break-beam eye system and contains the micro-switch that detects when the trigger is pulled. These components work together electronically to ensure the paintball marker fires accurately and quickly by sensing when a paintball is in the breech and when the trigger has been activated. • Eye system connection: The board connects the marker's "eye" system, which uses a break-beam to detect if a paintball is in the breech before firing. • Trigger micro-switch: It includes the micro-switch that is activated by the trigger pull, signaling the marker to fire. • Integration: The board, with its integrated electronics and micro-switch, is pre-programmed to function with the marker's electronic firing system. Part #73232