A bong bowl or slide is to attach to a bong for holding the dry herb. These removable bong pieces come in two sizes: 14mm and 18mm. All the bong bowls listing on Puffingbird.ca are made from high-quality borosilicate glass at affordable prices. Nice color and novelty design. We are carrying male and female deep-bowl slides to fitting your water pipes! Add some more for your bongs!