IR Break Beam Sensor – 5mm leds 

This IR break beam sensor works by detecting an object breaking a beam of IR light. This particular sensor has a range of up to 50 cm / 20″ and can be used with 3.3 or 5V. 

 raspberry pi 5 4gb  With a 64-bit quad-core Arm Cortex-A76 processor at 2.4GHz,  

argon one v3 raspberry pi 5 case

2 Channel 5V Active Low Relay Module