Tape & Reel (TR) is the package size of NTC thermistors. It's in the 0603 (1608 Metric) package for convenience. To make NTC thermistors work, the resistance tolerance is ±3%. The temperature of NTC thermistors should be set to -55°C~125°C in order to ensure reliable performance. It's 180mW power that the NTC thermistors can put out.