Small acrylic Rasta bong

Water pipes, or bongs, have a unique advantage that most other smoking methods don't: they filter and cool your smoke before you inhale it. In this process, the size of the bong and the amount of water it can hold are important. Some bongs even allow you to put ice in the straight tube that goes to the mouthpiece, making this smoke-cooling process even more feasible.

Yes. Always. It doesn't matter if you smoke your herb (and potentially tobacco) using the dry method (pipe) or water filtration method (bong), you should always use clean screens to protect your throat from burning particles. Simple screens are beneficial in many ways: most burning particles don't make it into your mouth, less herb is wasted, and they make it easier to clean your pipe/bong.

The most common bongs are made of acrylic, made of glass. They can also be made of ceramic or silicone. Each of these materials has its advantages and disadvantages, but the most commonly used bongs are made of acrylic (hard to break, cheaper but less pleasant to use) or glass (much more durable if they don't fall, more expensive but with more quality).