Lead safety clips have been used by carp anglers for years, I believe the main idea was to ensure safety for a hooked carp, if the lead became caught up in a snag or thick weed. The pressure applied by the lead onto the lead clip when pulled allows the lead to drop from the line. This means the carp angler can still manage to play a fish if a swivel lead becomes snagged up. This may help reduce the number of fish lost if hooked fish tend to race towards snagged areas or swim through thick weed. Also, if the main line breaks, which can often happen if there are weak points from frequent use of line, the fish wont have to carry a lump of lead around with them as it can easily come free giving the fish a chance to eventually lose the hook. The safety lead clips have benefits for both the angler and the carp. For these reasons they have become very popular with carp anglers, the great thing about lead clips is you can adjust how easily the lead comes free. This allows you to adapt to many carp fishing situations depending on the type of swim you’re fishing. When fishing near snags or heavy weed the rubber can be placed on half way so if the lead manages to catch any snags when the fish runs the lead will fall off quickly reducing the amount of fish lost, the lead clips also help when fishing at a distance and way past a large weed bed. If you hook a carp the weight of the lead will pull the line down onto the bed helping to keep the fish at depth, if the carp swims towards the weed bed there’s a chance you may lose it. However, if the rubber is pushed on very lightly it allows the lead to drop off as the fish is hooked, this will lighten the end tackle and you’ll be able to play the fish at the surface, bringing it over the large weed bed to the landing net. In this situation it would be best to lose a few leads than keep losing each fish AND most of the end tackle if snagged up heavily. The thing to remember is not to push the rubber on too tightly or super glue it on. This practice will render the lead clip ineffective when snagged because the carp cannot apply enough pressure to enable the lead to run free from the clip. In this case the swivel will pull free before the lead and you’ll end up with a running rig and a fish caught up, the video below is from Tim Reader showing the best practice when setting up a lead clip.