See Product Details

(1) Diameter for the buzzer
(2) For the rated voltage
Ex. 1.5V numbering by 01; 3.0V numbering by 03
(3) Serial number for various types
A,B,K: for the external drive with sealed type
C,D,F: for the internal drive with sealed type
G,H,J: for the external drive without sealed type
R,N: for the side emission hole design
M: for the bigger emission hold
Y: for the aside emission hold on the top of buzzer
S,T: for the type of SMD buzzer
(4) Numbering for various spec. of frequency, impedance & material
(5) Numbering for various spec. marketing or leads length
(6) For Wire type only (No number for pin type)