1,OEM offered 2,Good quality and good price. 3,Certificates: UL ... -1, CEM-1, CEM-3, FR-4 Halogen Free, Aluminium ect.Layer1-32Board Thickness0.4mm-3.2mmCopper Thickness0. ... Surface FinishHASL, Lead free HASL, OSP, Gold-plating, Chemical silver, Chemical gold(ENIG), Chemical tin, Carbon ink.Solder Mask ColorGreen, yellow, ... ,L/C or Western union high quality single layers lead free HASL pcb for electronic