This part is a kind of semiconductor called LM335.

Function of this product has PRECISION TEMPERATURE SENSORS.

Manufacturers : STMicroelectronics

Image and pinout :

Some of the text within the PDF file :

LM135 LM235-LM335,A PRECISION TEMPERATURE SENSORS . . . . DIRECTLY CALIBRATED IN oK 1oC INITIAL ACCURACY OPERATES FROM 450µA TO 5mA LESS THAN 1Ω DYNAMIC IMPEDANCE Z TO92 (Plastic Package DESCRIPTION The LM135, LM235, LM335 are precision temperature sensors which can be easily calibrated. They operate as a 2-terminal Zener and the breakdown voltage is directly proportional to the absolute temperature at 10mV/oK. The circuit has a dynamic impedance of less than 1Ω and operates within a range of current from 450µA to 5mA without alteration of its characteristics. Calibrated at +25oC, the LM135, LM235, LM335 have a typical error of less than 1oC over a 100oC temperature range. Unlike other sensors, the LM135, LM235, LM335 have a linear output. PIN CONNECTIONS TO9 [ ... ]

LM335 PDF Datasheet Download