Looking to buy a size L.

I had it in my cart and by the time I tried to check out, it said unavailable.

Would it generally be advised to stick to the same size as your UHF if you want to wear with an UHF under or size up?

I am eyeing the Navy one and won't be able to try these on in person.

Looking to buy a size L.

I had it in my cart and by the time I tried to check out, it said unavailable.