A riser if you wish to assemble your own base. The riser raises the box so you can create an entrance for the bees. 

The 3/8" riser set includes 3 natural timber pieces: 2 sides, and 1 back. 

The 1" riser set includes 4 natural timber pieces: 1 entrance, 2 sides, and 1 back. 

We recommend that you treat the timber with linseed oil or similar, to make it last longer. We also sell our 1" riser in ready-to-go form: assembled, waxed-dipped, and painted.