This part is a kind of semiconductor called SP1848.
Function of this product has Thermoelectric Cooler.
Manufacturers : Marlow
Image and pinout :
Some of the text within the PDF file :
marlow industries inc.® Thermoelectric Cooler Performance Values Hot Side Temperature (°C) ∆ Tmax (°C-dry N2): Qmax (watts): Imax (amps): Vmax (vdc): AC Resistance (ohms): 27°C 62.0 21.3 9.36 3.48 0.323 50°C 70.6 23.6 9.24 3.88 --- SP1848 Mechanical Characteristics 1.130 [28.70] 1.000 [25.4] 1.000 [25.4] Cold Side Negative Positive Hot Side Ceramic Material: Alumina (AC) Millimeters are in [ ] .192 [4.88] Ordering Options SP1848-00 SP1848-03 with out lead wire with 4” lead wire 102-0132, Rev A Thermoelectric Cooler Performance Curves Environment: One atmosphere dry nitrogen Hot Side Temperature: 27°C Hot Side Temperature: 50°C HEAT LOAD (WATTS) 0.00 2.50 5.00 7.50 10.0 12.5 15.0 17.5 20.0 SP1848 80.0 60.0 T (C) 40.0 20.0 0.0 HEAT LOAD (WATTS) [ ... ]