The Global Specialties EXP-350E Solderless Breadboard, 270 Tie-points offers molded interlocking edge rails on all four sides to permit parallel or perpendicular socket arrays, allowing more boards to be added at any point for maximum circuit design flexibility. The EXP-350E utilizes 0.3" DIP spacing and the molded-in mounting holes allow for either front or rear mounting. There is a heavy-duty Mylar backing to prevent short circuits. The integrated bus strips allow for fast connections to power and signal lines. Made from high impact plastic with phosphor bronze contacts.