29/11/2018 · 3. Polyethylene Snap Caps (72 hour storage) 4. Polyethylene Snap Plugs (Single Use) Why choose crimp cap vials? Crimp caps provide the tigh test seal,reducing the chance of sample evaporation.the 11.6*32mm crimp vials and 11mm aluminium crimp caps are economical and easy touse with vials crimping tools. Why choose sanp cap vials or crimp cap vials?