Two 18mm female joints create a flawless glass-on-glass seal between two male pieces. The sturdy palm-sized piece lets you boost your male rig to dual function. Slip your favorite 18mm male dry herb slide into the adapter to bring dry herb delight to the dab rig. Both ends of this excellent glass adapter measures 18mm in diameter. Use the adapter to convert a male joint into a female joint for pairing with male ash catchers and pre-coolers as well. Thick, high quality glass is durable enough to carry anywhere and stay strong between uses. This meticulously crafted glass adapter sits in an airtight seal with a frosted ground glass anchor. Just the right amount of friction creates the perfect fit. These interchangeable joints are easy to keep looking crisp with a simple soak or rinse. Browse our DopeBoo adapter selection to adjust joint sizes and angles, too! Glass adapters never cease to come in handy.