Bluetooth Audio Receiver and Playback Module (Bluetooth 4.0) [Discontinued] _RPI_HAT_Inputs Relay Quantity: 8

Relay Quantity: 8

And it's still very small at just 284mm x 127mm x 21mm

check out: eTape Liquid Level Sensor Datasheet

GPS Receiver for Arduino is a unit embedding GPS module and antenna in a small foot-print enclosure

Bluetooth Audio Receiver and Playback Module (Bluetooth 4.0) [Discontinued] _RPI_HAT_Inputs Relay Quantity: 8This Bluetooth Audio receiver module includes a USB port and TF card slot. With a pre amp output, you can drive headphones or a 3W speaker directly. You can also add an active power amplifier and connect a loudspeaker. The module supports MP3, WMA, WAV and lossless FLAC audio formats. This module supports playback from TF or USB flash drive. All playback is controlled by buttons, and an sound equalizer has build in to meet different favor. With its