The Golf Swing Shirt Training Aid
It's a little awkward but I guess that's the point to a degree. I have not utilized it over a long period to be able to allow real change that it's designed for.. but I would give it a solid 6/10 but it really depends on what your swing is alike and what you are trying to do.
Alex Fortey reviews the the golf swing shirt training aid.

The Golf Swing Shirt. It’s very well made, does a good job at what it's designed to do and that's to help you stay connected in your golf swing and it’s a perfect way to go through a checks-and-balance of my setup. That alone is enough to get a ringing endorsement from me that The Golf Swing Shirt is an excellent training aid,

Some points to note for the golf swing shirt. Get the correct size. Sizing is on their website and is based on height/weight. It needs to fit to work correctly.

-Good posture, including standing as upright at address as possible is the only way to have connection keep the club on plane, and not go ‘around’ your body.

-The shirt is good at keeping your arms on top of your chest, and together through the swing

The Golf Swing Shirt philosophy is partially derived from Hogan’s “Five Lessons”; specifically, as it relates to the importance of connection of the arms to the upper body.

This was something Hogan learned from Sam Byrd who was Jimmy Ballard’s teacher. What the Swing Shirt does is give you the feel of the triangle that Hogan and Ballard describe where your arms form a triangle with your chest that you move to the right, and then move to the left, using the ground and your legs as leverage to move the triangle.

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Please watch: “This Golf Swing Takeaway Adjustment Will Transform Your Consistency”
https://www.youtube.com/watch?v=-ilusL5td60
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