... 1.3" Compression Neodymium Driver 2.HF Driver 1.4" high frequency professional compression driver SE900 Top performance 1 ... FEA computer optimized lightweight Neodymium magnetassembly using a copper shorting ring produce smooth response,very high efficieny and outstanding sonic ... technology and quality. 3) Certificate: CE,RoHS,GS,SGS,ISO9001 4) Superb R& D and test technology with CLIO, SMARRT, ...