Buyers must prioritize cartridge capacity (typically 8g, 12g, 16g, or 88g) and threading type (threaded vs. non-threaded) to ensure compatibility with the intended device. The purity of the CO2 gas is critical; for food-grade applications like soda siphons, it must be 99.9% pure food-grade CO2, whereas industrial or sporting use (like tire inflators or airsoft) may have different moisture content standards. Additionally, verify the burst pressure rating and ensure the cartridges are made from high-tensile carbon steel with a corrosion-resistant coating (such as zinc plating) to prevent leakage during long-term storage.