True 4-Layer 2 oz Copper Scanner Head PCB with 28 Luddite_Coil_8mm Multilayer 8 mm OD Square Spiral Coils in a 2×14 Grid, 12 mm×18 mm Pitch, Individual MOSFET Drivers and Flyback Diodes per Coil, Bottom Layer Kept Component-Free #Luddite_Coil_8mm #2x14Grid #4Layer2Oz #CoilArray