This is the PCB/solder version of the Jumbo Dual LED Flasher kit. We also offer a breadboard-friendly Jumbo LED Flasher kit. This is an easy to assemble solder kit that is great for beginners or someone looking to add a flashing signal to their scale model projects. You can also use different color LEDs of your choice (sold separately). The flashing rate is adjustable with the two trimmer potentiometers.