This is a silicon impregnated cleaning pad that will revive your old fly line! There are 3 wipes in each package so you'll be able to clean multiple lines.
If your fly line is sinking (and you don't want it to), you've been fishing in some...questionable water, saltwater, or there's old dirt on your line these wipes are great for swiping over the line and cleaning it up!
These are in a very small package so it's very easy to keep a wipe on the water and clean as you fish! This is especially helpful if you travel a lot and don't want to carry a bottle of liquid around with you, which is the normal fly line cleaning solution.