The HC-12 433MHz Transceiver is a wireless communication Module, which is based on the RF SI4463 chip, has a built-in microcontroller and can be configured by AT commands, the maximum output power is 100mW (20dBm) and the receiver sensitivity differs from: 117dBm to -100dBm, depending on the transmission speed. Accepts 3.2V - 5.5V and can be used with 3.3V and 5V UART voltage devices.

In/Out Shield for your Arduino, Velleman.

The upgraded Input Shield for Arduino includes a two-axis mini-joystick (with moment switch) as well as four colored buttons (red, yellow, blue, green). The reserved interface of the APC220 Radio Data Module (SKU: TEL0005) and the Xbee interface are designed to make it easy to perform the wireless remote control button controller. The shield can easily be stacked on top of your Arduino boards. It can also connect with OLED2864 and OLED9664.

WiDo is a WIFI IoT Node development board compatible with Arduino.

The imported PL2303HX controller can stabilize the flash at high speed. With a 500mA auto-recovery fuse for protection and two data transmission indicators that can monitor the data transfer status in real time. The entire board is coated with a high-quality transparent heat-shrinkable layer, rendering the PCB in a state of isolation from the outside, so that the board is not burned. Electrostatic package, ensures that the plate will not be damaged before use. Supports WIN7 system.

MP3 Player Shield - SparkFun

The Vma210 Expansion Board is designed to allow easy access to the interface pins of an Arduino Nano. Each DIO pin or analog pin on the Nano is brought to an appropriate header.

The Sensor of Image Charmed Labs Pixy 2 CMUcam5 is smaller, faster and more capable than the original Pixy. Like its predecessor, Pixy2 can learn to detect objects, just by pressing a button. In addition, Pixy2 has new algorithms that detect and track lines for use with line following robots. The new algorithms can also detect intersections and "traffic signs". Traffic signs can tell your robot what to do, such as turning left, turning right, slowing down, etc.