Narrow-mouth septa bottles are available in clear or amber Type III glass equipped with a 0.045 in. thick blue PTFE/silicone septa in an open-top 24-414 polypropylene cap. The I-CHEM molded-in septa retainer ring holds the septa securely in place without bonding to the cap, so septa can be removed and replaced as needed. Amber is recommended for UV light sensitive samples. I-CHEM Certified® 200 and 300 series bottles are guaranteed to meet the EPA’s Performance Based Specifications for Volatile Organic Analysis.