I've purchased the medium of the red turtle neck which has a really fitted look. I've decided to get the black, beige and navy in large since I loved the red so much. I've decided to try out a new size just to see how it fits. I wear a 38R and 31 waist at 5.10. I've enclosed the photos of the medium red and the large beige for those interested to see how that fits. I think either works. The large is still somewhat fitted.

The turtle neck here can match anything from athleisure (shown here) all the way to smart casual jackets, leather jackets to maybe even a tux (if it's the smooth cotton version like the beige here). I like the versatility. This is a 10 out of 10 for me.

I've gotten the medium version of the red one, but since it's quite fitted, I've tried the large version of the beige one. I don't think it makes a huge difference, depending on your personal preference. I wear a 38R.

The flex in this fabric has allowed for both sizes to work well. As long as one is reasonably fit, this is an excellent addition. I also bought the black and blue in large because i liked it so much. I've enclosed the red in medium and beige in large for customers to compare the fit.