Active Buzzer is an integrated structure electronic transducers, DC voltage supply, widely used in computers, printers, copiers,
alarms, electronic toys, automotive electronic equipment, telephones, timers and other electronic products for sound device.
SD card shield is a Break out board for standard SD card. With flash memory card price dropping,it is the time to add mass storage and data logging to your project. You can select 3.3V or IO port power supply with the switch on board in order to work with different library.
This is a long distance 2.4G wireless module which basic on nRF24L01+ chip, and there is the PA and LNA circuit on board, with the external antenna it can reach long distance than the one without these parts.