Prototyping-Board-Protobloc-1-K-H-Manufacturing-KH-102-P-This-prototyping-board-protobloc-1-breadboard-is-a-prototyping-system-offering-a-fast-and-economical-method-of-circuit-construction-and-development-Solderless-in-concept-allowing-components-to-be-used-time-and-time-again-while-components-are-plugged-into-the-board-and-are-retained-by-double-leaf-spring-contacts-P-Incorporating-the-following-features-protobloc-prototyping-board-2-29-x-5-grid-size-390-number-of-holes-2-54mm