Bong joint adapters are small glass pieces that convert different joint sizes, joint genders or joint angles. If you want to use your 14mm bowl on your 18mm bong, we offer adapters that will sit in your bongs 18mm joint, and convert it to a 14mm! We also have joint adapters for male and female bongs, 10mm, 14mm, 18mm joints and some can convert 45 degrees angles as well! Having all of these adapters will allow you to truly utilize all of your bongs and bowls/dab nails.