Check the listing for details. SMD/SMT Electronics Soldering Practice Circuit Board Kit - Flip-Flop. Condition: New. Listed at 7.49 USD. SMD/SMT Soldering Practice Circuit Board Kit - Flip Flop Circuit This is a practice board I designed for those who are new to soldering surface mount parts or need some practice before jumping into a project. There are no parts smaller than 0603 case size. 107 items are to be placed on the board. 80 resistors, 20 capacitors, 2 LEDs, 2 transistors, 2 Zener diodes, and 1 Schottky diode. A reference is on the back of the board to help with identifying the parts. The circuit is a modern astable version of the Flip Flop circuit. Once power is applied, the LEDs should blink alternately about every second. While this is a simple circuit, it has several variations with many uses. Look it up! :) Note: this kit is not designed to teach how to solder SMD parts, but to practice what you've learned. Experience with soldering equipment is required. Thanks for looking. Check out my other kits! More to come...