The National Scientific Clear Glass EPA Vial is a 20mL, flat-bottom vial for water sampling for use with Aijiren Tech National vial convenience kits. The vial is 28mm in diameter and 57mm high, and accommodates size 24-400 caps (sold separately). When used with the appropriate cap and septa, this vial is recommended for discrete water sampling under the Environmental Protection Agency EPA 40 CFR 136 "Guidelines for Establishing Test Procedures for the Analysis of Pollutants" and EPA 40