The kit contains a prototype printed circuit board, breakout board, female header sockets. Compact structure, consisting of screw terminals, high-quality printed circuit board carrier, FR-4 fiberglass printed circuit board. The terminal module is made of high-quality materials and treated with fine craftsmanship for a long service life. Without assembly, there are various installation methods, which can be used flexibly. Specification: PCB: Printed Circuit Board Dimensions 12.024 x 7.72cm/4.73 x 3.04 inches Pad grid/spacing: 2.54mm/0.1", hole diameter 0.8mm. Terminal block spacing: 3.5mm/0.138", hole diameter 1.2mm. Terminal block: Pitch: 3.5mm/0.138" miniature terminal block, 84 pins in total (3 pins X24pcs, 2 pins X6pcs). Wire range: 26~16AWG, tape length 5mm, screw M2 steel, pin head, cage copper. Female socket: Pitch: 0.1"/2.54mm, pin length 15mm/0.59" Single row 10 pins x 1 piece, single row 8 pins x 5 pins, double row 18 pins x1 piece NOTE: This is not an original Arduino product. it's just a replacement accessory Delivery Quantity: 1 Piece