The Small GSI Lexan Dry Box has interior measurements of 5-1/2" wide X 4" front to back, by 2-7/8" deep. The dimensions are similar to the X-small size except for the depth. If you want to use this for a phone measure first before ordering.
Some of our customers have used this size and the Medium for holding rescue hardware like pulleys and carabiners for part of an "un-wrapping" kit, but then again those items don't need to stay dry. With a little foam padding this size can also work well for even some of the more bulky point & shoot cameras. We do have a $25 minimum order so keep that in mind when ordering on the shopping cart.