Compact 21mm Speaker with 8 Impedance 21mm diameter; 8 impedance; 0.25W power handling; 0-20kHz frequency range; 88±3dB sound pressure level; ideal for small electronic projects and audio alerts; Easy Integration for Arduino and Raspberry Pi Plug-and-play design; compatible with Arduino and Raspberry Pi; no complex circuitry needed; suitable for DIY, smart home, and game console applications; Stable Performance in Various Environments Plastic construction; long service life; stable operation under normal conditions; reliable for continuous use in consumer electronics and automation systems; Low Power Consumption for Extended Use 0.25W power rating; energy-efficient design; suitable for battery-powered devices; supports 72-hour operation in low-power mode; Clear Audio Output for Simple Applications High-quality sound reproduction; 88±3dB output level; easy to install; perfect for alarms, digital displays, and basic audio feedback systems