This is a replacement for the Princeton capacitive fuel probes. Princeton has recently been sold to RED Avionics. Working with my Princeton probe, which is less than a year old: we ust solved an aggravating problem. It is installed in an aluminum gas tank. On installation, it would show the calibration-failed error code every time. I sent it back and it was very thoroughly checked and re-calibrated no defects. Put it back in the plane with Mr. Stehouwer, the long-time owner of Princeton Electronics, on the phone, stepping through the power-up sequence, and we got the calibration error lights again. I loosened the five bolts holding the head down to the tank, recycled, and the calibration error did not re-appear. Apparently the probe was within a few hundredths of an inch of the bottom of the tank and the bolt torque on the rubber gasket was enough to make it touch. I put a short piece of acrylic tubing on the probe tip and verified it was too close to the bottom. Factory recommendation is for one half inch clearance between the probe and the bottom of the metal tank. Bending the probe slightly was enough to get the required clearance. The short to tank never happened when the probe was back at the shop for diagnosis, which was why he was never able to reproduce the problem. I really wish I had checked clearance to the tank bottom with a piece of tubing when I installed the probe the first time. Many thanks to Todd Stehouwer for being so patient with me and working through this.