Day Zero Survival Ring Self Defense Knuckle Mini Stun Gunn. This small hand held (and easily concealed) stun gun delivers a powerful shock to anyone who tries to assault or rob you. Often just air firing it, which creates a loud spark, is enough to warn anyone with half a brain to back off and leave you alone. No one likes the sound of a potential electric shock. The rubberized case provides a firm grip and weather resistance. Dimensions: 3” long x 3” wide and 1” thick