SFM-27 95 dB Continuous Beep Buzzer, 3 to 24 V, Pack of 5

A panel that has to make itself heard needs a tone, not a tune. This SFM-27 buzzer puts out a continuous beep at 95 dB measured 10 cm away, runs from 3 to 24 V and arrives five to a pack. For alarm boards, timers and Arduino builds that need an audible step.

A steady tone for a board that needs one

✅ Heard over bench noise At 95 dB at 10 cm the tone sits above a workshop fan or a busy kitchen.

✅ One part, mixed rails The 3 to 24 V range covers a 5 V board and a 12 V panel alike.

✅ Steady, not musical It holds one continuous beep while powered, which suits a fault alarm rather than a chime.

✅ Spares in the drawer Five arrive in the pack, so a build does not stop for one failed buzzer.

✅ Two wires, two holes Leads are fitted and two holes 40 mm apart let the body sit squarely on a panel.

The buzzer is a sounder, not a sensor: nothing in it detects movement, smoke or water, and it makes its tone whenever the supply is live. A switch, a timer, a relay or a board output decides when that happens, and the buzzer supplies the sound.

Wiring is two leads and a DC supply between 3 and 24 V, with a rated voltage of 12 V and a maximum draw of 20 mA. The resonant frequency is around 3.1 kHz, which is where the tone comes through most clearly over background noise.

The body is 29 mm across and 15 mm tall, with two mounting holes 40 mm apart and 105 mm leads. That spacing is the figure to check against the panel or the enclosure before drilling, and the pack of five covers a set of boards rather than a single build.

Technical details

• Model: SFM-27
• Quantity: 5 buzzers per pack
• Rated voltage: 12 V
• Operating voltage: 3 to 24 V
• Current: 20 mA maximum
• Sound output: 95 dB at 10 cm, minimum
• Resonant frequency: 3100 Hz, plus or minus 500 Hz
• Diameter: 29 mm
• Height: 15 mm
• Mounting: 2 holes, 40 mm apart; 105 mm leads

Match the supply on your board, then keep the spare buzzers in the parts drawer.

See more: explore more audio and sound components