Containers in Polypropylene in various sizes with colored caps. I deal for sampling and storage of samples where the integrity of the sample if of high importance. Once the container is sealed it can not be opened again unless the security seal is broken, the cap is also reusable for normal resealing after opening. Chemically resistant to most chemicals. Containers come in various sizes and is Ideal for drug tests and forensic sampling. Containers is also available in sterile single wrapped option. Lids is also available separately for resealing purposes.