The Killzone is a innovative new product which revolutionizes rigging for anyone who uses a 3 ways rig.
 
 
It also allows for adding a attachment point to the line without cutting and tying new rigs.
 
#1 Strength - They held 106+ pounds of pressure during one of my test with that strapped and rigged to a 1 inch dowel rod and my crane scale and didn't fail! No-one will ever put 106 pounds of pressure on a catfish on a rod and reel.
#2 I won't say these can't tangle but I have bumped a 4 inch plastic swim bait down the river for miles in 2.3 MPG current without a tangle. I've never done that with a standard 3 way swivel.
#3 the speed and ease of switching rigs, replacing broken rigs, weight leaders, etc., is vastly faster and easier with the Killzone.
#4 is adjustability and versatility. With these I can add a second rig, floater, or any attachment point to my line that I want and not have to cut or retie a new swivel or attachment point. I just attach a separate Killzone and I'm good to go.
#5 When packing up, I just unsnap my bait leaders and my weight leaders and the only thing left on my line is a Killzone and a barrel swivel. No hooks to get hung up. No heavy weights damaging my rods. Nothing to worry about. I'm good to go. #6 I rarely loose a Killzone because I'm running a 65# braid main line with a 50 pound hook leader and a 20 pound weight leader. If I sinker gets snagged, I loose it. If a hook leader gets snagged, I loose it. I've never gotten the Killzone snagged and lost one while fishing, YET!