These are more solid feeling than I expected--very well made. Lid screws on easily and cap snaps shut with a reassuring snap. You can safely shake away without concern for any leakage. And the shaker with the wire ball makes short work of my protein powder drink. I find that cleaning is simply a matter of rinsing; though I do clean with dish soap now and again...just because. Highly recommended. Can't think of one ding!