緊實

Wasn't sure about the whole adjustable thing at first, but the lock mechanism actually stays put once you set it, no slipping mid-way through. Finding the right fit took me two tries and then it just worked.

The adjust-and-lock design took a couple tries to dial in, but once I found the right fit it stayed put the whole time. Way better control than the fixed-size one I had before.

The lock mechanism holds firm even when things get vigorous, so no worrying about it slipping mid-session. My partner and I both noticed the difference in how long we could last before needing a break.