Butterfly Hose Clamp - 1/2 in.

Functions the same as a standard Hose Clamp, however rather than needing to find a screwdriver (or dime!) for every adjustment you can easily tighten by hand.

As an added bonus, this also has a significantly smoother inside to the clamp, which will not tear up your tubing nearly as much as a standard hose clamp!  Ideal for situations where you need to remove tubing from fittings to sanitize.
 
Please note, as the reviews will also tell you, this is a clamp that will fit 1/2" OD tubing. If you are looking for a clamp for 1/2" ID (with 3/4" OD) choose the H955 clamp.