Best range booster

[KingDad1985]

I'm looking for the best copper signal booster. When I fly in my neighborhood If I click on the ready to fly green button on dji go app it keeps going from poor to good on signal strength. I found a few on amazon that is copper and goes over the antennas. About 20 dollars and is made by skyreat, arieltek, hobbyace, btg, etc.
Soooooo which is best? Thank you

 

[flpholt]

pretty much all the same

 

[KingDad1985]

pretty much all the same

Don't they actually work?

 

[flpholt]

they work okay if in open area but if you want something better go with dbs mod maxxuav.com check them out