The Azden SGM-990 is a versatile and compact electret condenser shotgun microphone designed for enhanced audio capture with DSLR cameras, camcorders, and field recorders. Handcrafted in Japan, this directional "zoom" microphone offers a significant upgrade over standard built-in camera microphones by focusing sound capture and rejecting unwanted noise from the sides and rear. Its defining feature is a two-position switch that allows the user to quickly change the pickup pattern between "Long" (super-cardioid) for distant sound sources and "Short" (cardioid) for closer subjects. This adaptability makes it suitable for a variety of recording environments, from intimate interviews to outdoor events.

Operating on a single AAA battery, the SGM-990 provides reliable power autonomy, with some reports suggesting battery life of approximately 1000 hours of use. The microphone is built with a durable electret condenser element and outputs audio via a coiled cable terminating in a standard 3.5mm (1/8") mini-jack connector, plugging directly into most camera microphone input jacks.

The microphone's performance is characterized by a wide frequency response of 150 Hz to 18 kHz, optimized for capturing clear human speech and general environmental sounds. It is a popular choice for videographers seeking a balance of performance, affordability, and ease of use, providing a working range of approximately 20 to 40 feet depending on the setting.