These are 100% cotton so bear in mind they won't give a consistently tight fit.  They will be snug after you take them out of the dryer but they loosen up as you wear them.

The leg holes on these are a little bit smaller than very similar CK boxer briefs I bought a year or so ago.  They still fit OK but any smaller and they would be too tight.  If you have large thighs you might be initially strangled by the mediums.  Though as I mentioned they do loosen up with wear.

These briefs are the CKs that have a lighter gauge cotton.  I'm not sure how one is supposed to know in advance how thick the cotton is.  I really wish CK would simplify their branding so it is easy to find the same style, thickness, size, etc every single time.  Also, if you are looking for a skin tight fit go with CKs synthetic blends--not the 100% cotton.