- Open at large end, with uniform taper similar to that of rubber stoppers
- Hollow shell polyethylene construction affords sufficient flexibility to provide secure seal
- Top edge is reinforced to increase rigidity
Can also be inverted for use as loose or tight-fitting caps. Smooth inside walls and flat bottoms permit use as containers. Length of all sizes: 25 mm. Stopper sizes, corresponding generally to standard numbering of laboratory rubber stoppers and top x bottom o.d. in millimeters are shown in listings.