This lock box is exceptionally well made and finished. I purchased two of them and mounted one under a desk top (had to mount upside down because the pre-punched holes were only on the bottom). The other unit sits on a two drawer filing cabinet. I utilized two of the 1" punch outs located on the back of the unit to secure the lock box to a pedestal desk using a Kryptonite bicycle cable lock. The electric fan runs 24/7/365 and is very quiet although you can hear it. (The slight hum is almost pleasant.)The box measures 23 1/2" x 20 1/4" x 5 1/2" and is much larger than my DVR required. This may be a good thing as the extra space inside allows the DVR to be turned enough to connect and disconnect cables with ease. I would recommend this lockbox to anyone wanting to secure their security camera DVR.