1) What is the difference in those two? I am building a redoing a squier strat and I want to put new locking tuners. The guitar is left handed, which one of the do I need, i'm not sure if they mean for a lefty headstock or someone tuning with their left hand. Kind of new to me..

2) Anyone have any experience with Gotoh tuners? They any good IYO?

3) How do locking tuners work? How do they make a difference..

Thanks in advance UG!!
First of all, you want the black ones for the left handed guitar.
Locking Tuners tighten down on the string on the tuning head and keep the guitar in tune way longer than normal. I recommend them.
Locking tuners are great. I have Gotoh's on all my guitars... Great. Reliable...

If it is a lefty guitar, get left-handed.
Ibanez RG42DX
Peavey Valveking100
Avatar 4x12 cabinet w/ Celestion Vintage 30's
Line 6 Spider 3
DOD Flanger
Ernie Ball Strings
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Peavey TNT 135
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Unless you want to have to turn em backwards then yes you will need lefties. I can tell you its no fun to have one guitar you need to remember to turn the tuners the wrong way on.