The best shelter for an existing busy Orchard Mason Bee population or big dreams. This reusable, cleanable wood block with 96 holes, that on average are filled with 8 to 10 cocoons each, can be used with the System's white paper liners. The System's liner make harvesting cocoons much faster.  It does come apart to easily to harvest your cocoons. A recommended location for your Orchard Mason Bee shelter is on the side of a building, under an eave in the sunniest location available.