Main Board:
L5 Standard Main Board, Green LEDs $220
L6 Standard Main Board, Red LEDs $220
L7 Extended Main Board, Green LEDs $220
L8 Extended Main Board, Red LEDs $220
Note: The Standard Main Board handles up or down totalizing as well as frequency, rate, period, square root of rate, and A-to-B time interval. The Extended Main Board handles the above plus simultaneous rate and total, stopwatch, arithmetic functions, phase, batching, and custom curve linearization.
Power:
0 Isolated 85-264 Vac & 90-370 Vdc NC
1 Isolated 8-28 Vac & 9-37 Vdc $30
Setpoint Output:
0 None NC
1 Dual 10A Contact Relays $80
2 Isolated Dual Solid State Relays $55
Second Output:
0 None NC 
1 Isolated 0-20 mA & 0-10V $90
2 Batch Relay. Only used w/pulse-input batching operation. $50
Digital Interface:
0 None NC
1 Isolated RS-232 $60
2 Isolated RS-485 $80
3 Isolated Parallel BCD Output $105
Add-on Options:
EB Extra Bright Red LED Display $30