This is unassembled version, SOLDERING REQUIRED, so you can make flexible use. The kit included: I/O extension PCB, 1 pcs. Male header, 120 pins. Female Header Socket, 1x 10pin, 5x 8pin, 1x 36pin(dual row). Ø5mm green LED, 1 pcs. 300 ohm 1/4W resistor, 1 pcs. 47uF/35V SMD electrolytic capacitor. 6x6x5mm tactile switch, 1 pcs. PCB Dimension: 101.6mm x 53.34mm / 4" x 2.1" PCB thickness 1.6mm, high quality FR-4 glass fiber PCB. Male header pitch 0.1"/2.54mm, pin height (from PCB to top) 8.5mm / 0.34" Female Header Socket pitch 0.1"/2.54mm, pin length 15mm / 0.59" Note: the item not include Arduino MEGA 2560 module.