+3 18.8mm Male stem for Twist/Maxx/Flip Brick FL5118MS $14.95 In stock Quantity: 1 Add to Bag Product Details Replacement for the Twist, Flip, and Maxx 18.8mm male stem. This will also work with our new injector chamber.Our glass is made in-house using the highest quality scientific German joints. Save this product for later Favorite