ETI Research BP-20C Binding Post (par)The ETI Research BP 20C Binding Post is a superb high performance Binding Post available at an entry level price. Made from 1100 Series Hardened Copper with an IAC Rating of 102%. You can rest assured the audio signal is not being degraded by having to go through a poorly conductive material such as Brass. CONDUCTOR Gold Plated 1100 Series Copper HOUSING Brass (Black Finish) Copper is far superior to Brass in terms of conductivity and as such the BP