The Global Specialties EXP-355 Solderless Breadboard has 470 tie-points and offers unlimited circuit design expansion though its unique molded-in interlocking edge rails. It offers 0.3" DIP spacing, and its unique molded-in mounting holes allow for either front or rear mounting. Molded interlocking edge rails on all four sides permit parallel or perpendicular socket arrays, allowing more boards to be added at any point for maximum circuit design flexibility. The integrated bus strips allow for fast connections to power and signal lines. The EXP-355 is made from high impact plastic with phosphor bronze contacts. It has a heavy-duty Mylar backing to prevent short circuits.