This is a high quality FR2 / Paper Phenolic PCB. – It is used for rapid prototyping design. – Product Name : FR2 SINGLE Sided Copper Clad Circuit Board PCB 6 x 4 Inch Paper Phenolic; – Size(Approx) : 6 x 4 Inch; Layers : Single Sided; Material : FR2 A Grade Material; Surface Finishing : Copper Clad; -Package Content : 10 x FR2 SINGLE Sided Copper Clad Circuit Board PCB 6 x 4 Inch Paper Phenolic Universal PCB Circuit Board Sheet for DIY. Please Note : FR2 (Phenolic) material is different than FR4 (Glass Epoxy)