Laser Sensor Module 650nm 6mm Red Laser Dot Diode Copper Head – diymore
10pcs 3v-5v 650nm Adjustable Mini Laser Sensor Module 5mw Arduino Red Laser Spot Diode Copper Head Level Meter Ground Wire Meter - Sensors - AliExpress
Waveshare Laser Receiver Module Sensor Transmitter for Arduino AVR Pic for sale online | eBay
How to build an optical/light barrier with the Arduino, the Keyes laser module (KY-008) and a laser receiver/detector module - Michael Schoeffler
Horizontal laser harp is like none you've ever seen before | Arduino Blog