Flangeless Fittings are easy to assemble; slide the ferrule over the tubing and finger tighten the nut. No need to flange your PTFE(R) tubing. Models 01939-30, -32 take 1/16" OD tubing and are rated at 1000 psi; models 01939-32, -42 take 1/8" OD tubing and are rated at 500 psi. Feature 1/4-28 threads.