... FR-4 Thickness: 1.6mm Surface finish: HASL CE, UL, ROHS approved Specifications: 1) Double layer PCB, 1.6MM2) Strict quality control3 ... board size: single, double sided 22'' x43'' (550x1100mm) multilayer 22'' x25'' (550x640mm)Impedance control: ±10%Surface finish: OSP ... electronic gold, ENIG, gold finger, immersion silver, immersion tin, thick gold platingBase material: FR4 (Shengyi, KB, Intl.); High ...