I have all three versions of the ASP Defender OC's. I find them relatively easy to carry and I believe they add a potentially useful component to my EDC. However I made an error over the last few years, I had not opened up the defender and looked at the expiration date. I found I had two expired cartridges, one was 4 years out of date and the second was 2 years out of date. I headed to the backyard and decided to see if the expiration date really mattered. Neither of the expired cartridges sprayed in any sort of useful manner. The product just dripped out, maybe about one foot from the nozzle. Thankfully I have not needed or tired to use either expired spray. The largest of the set, the Street Defender expires in about 12 months from now. I tried it in the back hard and it sprayed in a nice cone pattern approximately four feet into the bush I chose to spray. I deliberately chose a windy day to judge blow back. I had discharged the unit for about 1/2 second. I did receive mild blow back that I would compare to a mild jalapeno pepper. My sinuses were opened, so it wasn't terrible, but I could tell that I would not want a face full. I have since ordered replacement cartridges and all are now up to date. I will continue to carry the units, although I did find the volume in the Palm Defender to be abysmal and probably not worth it. All the sprays contain dye as well. I wanted to share my experience, feel free to ask any questions. Left to Right: 15 round ETS Glock magazine for scale, Palm Defender, Key Defender, Street Defender
A mini-Mag lite clip like this one: https://www.amazon.com/Maglite-Mini-Flashlight-Accessory-Pack/dp/B00002ND52/ref=sr_1_1?ie=UTF8&qid=1526963880&sr=8-1&keywords=mini+maglite+clip will fit the Key Defender. That's how I carry mine. I've replaced the cartridge once in a while but never had to use it.