I purchased the bullet blocker underwear.
They sagged to the point of falling off every 5 steps. I contacted customer support. They had me switch for a smaller size, which also meant smaller plates.
They still fall, now about every 15 steps. I think they should add drawstring.
I bought bodybeast level IIIa from another company. Love it, my favorite armor.
I bought dfndr level 4. Very nice, lightweight for level 4.
I bought cati level 3+, very heavy, but good.
I even bought t-shirt carrier, very discreet. Good.
Finally, the gabriel down undergarment from bullet blocker. It's my favorite IDEA, but LEAST favorite armor out of everything I have.