These are 2.3x2.3x5.07" boxes which work great for fossorial (or arboreal slings). The vent being at the top helps prevent it from being covered when your precious digger moves dirt around and redecorates. These enclosures will also work perfectly well for arboreal spiderlings, though we don't recommend for Aviculariianae sp, as we have better designs available for those.
Our ventilated versions have a single 1" Screen vent, in the lid which is available in 4 different colors. We also offer the unmodified box for those who wish to create their own ventilation.