Never heard of this crazy thing but saw someone of my local Facebook market place selling one. So it fuses the line together or something to eliminate the need to tie a knot? If someone was on my boat and pulled on of these out I would throw them in the lake! $200 on Amazon though:

 

https://www.amazon.com/Tauten-LineWelder-Automatic-Fishing-Line/dp/B01KP7ZU5W/ref=sr_1_1_sspa?ie=UTF8&qid=1547345474&sr=8-1-spons&keywords=tauten+line+welder&psc=1

for free i'd try one...not sure it would work to well with braid though lol

 

10 hours ago, flyfisher said:

for free i'd try one...not sure it would work to well with braid though lol

 

It says it works with braid to mono. It looks like maybe it's a hot-melt glue. The joint looks too big to go through guides smoothly, so it wouldn't be any good for a leader.

 

At first I thought maybe it would be good for someone who is disabled, or someone who has severe arthritis or something, but after looking at it, it's way too complicated for that. You even have to wipe the line with alcohol before using it.

 

I can't imagine who could have a use for this thing.

Was this on Shark Tank once??

Yup.