Can be used for liquid scintillation counting, gamma counting, chromatography, sample storage and culturing. It will fit very nicely into the LKB and Packard Varisette counters. The shoulderless vial features a full width opening of 12.5mm and the overall dimensions are 16 x 57mm. The closures are made of high-flow polypropylene and are a true time saver. The vials can be securely sealed by simply snapping the caps on; removal of caps requires an easy 1/4 turn (twist). The ease with which these caps can be manipulated eliminates the danger of spillage associated with other push-on/pull-off caps. A built-in positive lock prevents the cap from popping off because of a small build-up of pressure in the vial.