This part is a kind of semiconductor called KSD301A.

Function of this product has Thermostat.

Manufacturers : Sunshine

Image and pinout :

Some of the text within the PDF file :

Thermostat KSD301 SPECIFICATION Electrical Rating : 16A 125V AC (Resistive Load) 10A 250V AC (Resistive Load) 16A 250V AC (Resistive Load) Operating Temp : 50 ~ 175 (UL.CUL 205 ) Differential : 10~30K (15K Standard) Temp. Tolerance : Operating Temp. 3K 5K Heat Durability : 220 Max. (PPS) Circuit Resistance : 50m Max. Insulation Resistance : 100M Min.at DC500V Dielectric Strength : AC 1000V for One Minute. or AC 1800V for One Second. Operating Life : 100000 Cycles (16A 125V/10A 250V AC) 10000 Cycles (16A 250V AC) HOW TO ORDER MODEL CODE (FULL CODE) Ex) KSD301 A 1 10 B C D 2 B MODEL SERIES (a) CONTACT TYPE OPERATING TEMP. TEMP. TOLERANCE BRACKET TYPE TERMINAL ORIENTATION TERMINAL SIZE BASE MATERIAL B : Bakelite C : Ceramic (a) CONTACT TYPE : (b) (c) (d) (e) A = Contact Opens W [ ... ]

KSD301A PDF Datasheet Download