Detailed Product Description Single layer circuit board· FR1 Single Sided PCB with Peelable Mask, V-Score. · FR4 Single Sided PCB with Red ... Peelable Mask, White Legend, Hole & Contour Punched. · FR1 Single Sided PCB with Green Soldermask, Yellow Legend, Hole & Contour ... Punched. · FR4 Single Sided PCB with CNC Drilled Holes, Black Soldermask, White legend ...