The silicone has just enough give that it doesn't pinch, but it still holds firm where it counts. The opening at the base really does keep everything in place, which made way more difference than I expected.
Sebastian★★★★★
Wasn't sure the opening at the base would actually do anything, but it really does keep everything in place instead of pulling up. The silicone is firm enough to stay put yet soft enough to wear for a while.
Benjamin J.★★★★★
The 35 mm size hits the sweet spot for me, snug without feeling like it's cutting off circulation. The firm silicone barely stretches, but the ball opening at the base is what really makes it work.