Upgrade your Model 3411 or 3401 Troxler nuclear gauge with the Advanced Control Unit. The ACU will transform an older gauge into a more modern gauge, very similar to the current Model 3430. Special functions are available at the press of a button. Offsets are applied with a simple series of keypresses - no more knobs and switches. Upgrade your Troxler gauge today with this authentic Troxler Advanced Control Unit to be sure to get only the best and most reliable parts, service and support.