These are 2.3x2.3x5.07" boxes which work great for arboreal ( or fossorial) slings. I recommend this style for Non-Aviculariianae arboreals as we have some middle/bottom open enclosures which are more ideal for avicularia and related species. This enclosure will also work fine for fossorial slings, but be also have a similar one with the vent on the lid, which will make it less likely to be barricaded by dirt that we would recommend for those buldozing species.
Our ventilated versions have a single 1" Screen vent on the side near the top, available in 4 different colors and it can be found on our listing for the Spiderling Fossorial Enclosure