The T Series was designed to be used as a cap or a plug and are tapered to fit a wide range of applications to protect from contaminants and debris. These caps/plugs may be used for mil Std, sae-type fittings, hydraulic and threaded or non threaded fittings. The tapered design allows the opportunity to cover a vast range of cap or plug applications. Easy to install or remove.:: a: 0.915, b: 1.04, C: 0.855, D: 0.98, E: 0.69, F: 1.16.