These are four high-quality glass bowls designed to enhance your smoking experience. Two bowls are 14mm to fit smaller pipes or bongs while the other two are 18mm to fit larger ones. Each bowl is made from thick and durable glass, ensuring that they can withstand daily use. The added convenience of having two different sizes allows for versatility in your smoking setup. These bowls are an excellent addition to any avid smoker's collection and are sure to provide a smooth, enjoyable hit every time.