Conserve your waxes and oils in style by augmenting your favorite dab rig with this sophisticated Bell Top Glass Carb Cap. Without a carb cap, you risk having to heat your dabs at higher temperatures and therefore lose flavor. Get the best your concentrates have to offer by investing in a heat resistant carb cap. Waxes, oils and other concentrates taste better and heat more efficiently with a carb cap attachment improving your piece. Assorted Colors.