Description. Description: 500mL, PETG, Squared Media Bottle, Sterile/Non-sterile. Purpose: Ideal for mixing, sampling and storage. Materials: Bottle: PETG (Polyethylene Terephthalate Glycol) Color: Clear. Cap: HDPE (High- Density Polyethylene) Color: Natural. Features: Crystal-clear PETG is robust and break resistant, increasing personal safety