The Rampage board for the BT4 is a direct Drop-In replacement for your existing E-Grip.
 
This board features:
State-of-the-art RISC Microcontroller
Weather Resistant Conformal Coating protects your electronics in the Rain! 
Extended Battery Life Simple Push Button Selection to Change Firing Modes
Visual LED Mode Indicator – Visible in Direct Sunlight!
User Programmable Firing Mode Enabler – You decide what modes are enabled or disabled
Rate of Fire from 5 to 30bps!
Adjustable Dwell and Debounce
Programmable Burst Mode
Programmable Rampage Mode
Programmable Turbo+ Mode
 
8 Base Firing Modes:
Semi Automatic
Burst
Reactive 
TRUE Full Automatic
Turbo+
Rampage™
PSP3
NXL