The Lighthouse Quadrum coin holder system combines attractive and durable 2x2 snaplock coin holders with a variety of display boxes and other storage mechanisms that together result in an attractive display system for almost any collection or combination of coins. The high quality, durable and scratch resistant hard plastic holders offer optimal protection. Your coins are accented against a black insert which is available in sizes ranging from 14mm to 41mm. With this range of sizes, there is a Quadrum holder for virtually every coin. Quadrum holders snap together securely, yet are easy to open. Both the holders and the inserts are chemically inert and free of PVC, acids or softners. The consistent outer dimension of Quadrum holders allows different sizes of Quadrum holders to be mixed and matched for storage or display in a variety of bulk 2x2 storage boxes, display cases and album pages.