Review on 🌡️ AGPtEK F/C PID Temperature Controller with Dual Display and Programmable Digital Control TA4-SSR Solid State Relay - 2 Alarms Included by Piyush Ventura

I can't win with these little TA-4 controllers. The first had some pretty serious accuracy issues using a type K thermocouple. It wasn't linear so it couldn't be calibrated (10F too high in an ice bath, 11F too low at room temperature, 15F too high with boiling water ). The second block read the exact same TC perfectly, but it was the mechanical relay version, not the SSR version (although I ordered the TA4-SNR). The 3rd order was the same as the 2nd (TA4-RNR instead of TA4-SNR). The problem is that the box has stickers for BOTH devices. The sticker above mentions SSR, and the sticker on the much less visible end says Relay. From the seller's point of view looking at the top of the box, it looks like they are shipping the right item! I can't recommend buying from BrainyDeal or Sain Store (are they the same?) until they fix this issue. I bet some of these things are mislabeled and this problem will persist. The TA4-RNR version I tested worked great, but my project required SSR so it couldn't be used.