This part is a kind of semiconductor called HY-05.

Function of this product has ELECTRO-MAGNETIC SOUND GENERATOR (Buzzer).

Manufacturers : HYCOM

Image and pinout :

Some of the text within the PDF file :

ELECTRO-MAGNETIC SOUND GENERATOR HY-05 DEVICE MANUFACTURING DEVICE MANUFACTURING FEATURE NON-MECHANICAL CONTACTS AFFORD HIGH RELIABILITY AND LONG LIFE. HIGH SOUND PRESSURE AND NO ELECTRIC NOISE. STABILIZED SOUND QUALITY. SEALED DESIGN FOR AUTOMATIC SOLDERING AND WASHING. SPECIFICATIONS RATED VOLTAGE (V) 5.0 OPERATING VOLTAGE (V) 3.0 ~ 8.0 CURRENT CONSUMPTION DC RESISTANCE (mA) (ohm) 50 Max 40 + 10 % SOUND OUTPUT AT 10CM* RESONANCE FREQUENCY (dB) 85 Min. (HZ) 2400 + 200 OPERATING TEMPERATURE ( C) 20 ~ +85 WEIGHT (gm) 2.0 * VALUE APPLYING RATED VOLTAGE, 2400 HZ, 1/2 DUTY, SQUARE WAVE. OUTLINE DIMENSIONS HYYC-0O5 0.6 H 6.5_+ 0.4 12.0 M 2.9~3.2 10.0 Unit : mm Tolerance : +_ 0.5mm FREQUENCY CHARACTERISTICS dB 100 90 80 70 60 50 500 1K 2K 5K 10KHz POWER INPUT : 5.0 V [ ... ]

HY-05 PDF Datasheet Download