The Type 26 nest box is suitable for redstarts, pied wagtails, spotted flycatchers and sometimes. The box dimensions correspond to those of standard, commercially available bricks used in modern European construction. These dimensions allow for a 1cm layer of mortar enabling the nesting blocks to be inserted in any wall without cutting adjoining bricks. The box can be installed flush with the outside wall and can be rendered or covered so that only the entrance hole is visible.
The interior of the box resembles a natural woodpecker hole, with the same shallow, oval depression in the floor. The box is manufactured from virtually the same material as Schwegler's tried and tested wood-concrete; an exceedingly durable, rot-proof and breathable natural material designed to mimic the properties of natural nest sites.