A 40H is a 40 band with an H cup — a deep cup that's hard to find on the high street. The band does most of the work (around 80% of your support), so if it rides up at the back or the straps dig in, it's the band to fix, not you.
We cut 40H for fuller busts, part of our full 40D–40K range. Not sure 40H is your size? Book a personalized fitting and we'll get it sorted.