Connect your micro tubing to standard size tubing or luer fitting systems. These TEFZEL® adapters are designed for use with small tubing fittings. Adapters come with either caps or with a 1/4-28 UNF thread and lock nut. Adapters with caps include zero dead volume PTFE cones and screw onto the fitting body. Adapters with 1/4-28 UNF thread come with lock nuts and screw directly into existing fitting caps.