Junior high school presentation group. The product is composed of circuit board, component insert, plug connection device, special connection and so on. The bottom line is 4 pieces, made of plastic, the size is 360 x 240 x 20mm, 96 hole, aperture diameter is 6mm, pitch is 30mm. Components in block is  made of engineering plastics production, divided into big two hole socket, small two hole socket, four hole socket and the battery socket, and the surface of each module mark is arranged in the component name or circuit symbol. Big two hole socket dimensions : 85.5 * 51 * 30MM, small two hole socket size: 58 * 24.5 * 26mm, four hole socket size: 84 * 84 * 36mm, battery holder in block size: 88 x 40 x 44mm (1# cell, six in total).