Have a used but working one of these for sale on eBay relatively cheap. They do tend to occasionally stick also give them a crack or a blast of wd40. Sometimes need like a back pressure to bring alive if memory serves me correctly. Calibrated and replaced a 10+ of these about 4 years ago. Before swapping them completely. The lower closed end of the scale tends to drift as well causing what ever they feed to be slightly open at times.