This is a very useful niche-filling device. I carry one of these every day. It is reloadable, easy to use, easy to carry in pocket or in a holster (also pictured). It has a metal alloy-frame, lacks obnoxious protrusions, and doesn't weigh too much.
The ergonomics are similar to a small-framed revolver and in fact, the safety is located where the hammer would be on an actual revolver -- just pull back to fire. The stream of pepper spray looks like it's coming from a super-soaker. You can hold the trigger down for one long stream, or use it in several shorter blasts. It has very good range, about 25 feet.
There is an LED light built into the device at the top of the trigger-guard front. Taking up the slack on the trigger activates the light. This may cause your assailant to lose his night vision or focus in on it just in time to receive a healthy dose of pepper spray. We have a good deal on it here. I enthusiastically recommend this item and use it myself. You can quietly acquire your grip while it is still pocketed and be ready when things go sour.