Secure another level to an existing, plastic S&K martin house or keep the roof and walls anchored in place using these S&K House Snaps. This bundle of 26 two-piece, black plastic snaps is compatible with the BN-16 or PBH-12 plastic purple martin homes. An expanding sleeve inserts into the holes on the roof or side panels of your existing martin home, and the 1/2" long, threaded section installs into this base. Once inserted, the lower section extends outward, joining the pieces of your martin house together securely for longevity. These durable anchors each sport a wide cap to block water from seeping in below them, and their plastic construction remains durable. Build or expand an existing, plastic purple martin house with these House Snaps.