This is a very small light sensor. A photo resistor (also known as a photodector, or photocell) changes resistance depending on the amount of light it is exposed to.
The HC-SR501 is a passive infro-red (PIR) sensor which is used to detect motion based on the infrared heat in the surrounding area.
The H8054 PIR motion detection module provides basic motion detection in a small package. Compatible with the Arduino and Raspberry Pi
Open Box - The MGS1600GY is a sensor capable of detecting and reporting the position of a magnetic field (typically magnetic tape on the floor) along its horizontal axis. with custom aluminum mounting bracket
900 MHz Rubber Duck Antenna - SMA Male Connector