BK10 Hybrid FPC-to-Board Connectors Hirose Electric BK10 Hybrid FPC-to-Board Connectors are ultra-low-profile, 30-position flexible printed circuits (FPC)-to-board connectors. The BK10 connectors feature a 0.5mm stacking height and a 1.7mm width that provides significant space savings. Combining a miniature design with a rugged, fully armored housing makes the BK10 components ideal for a wide range of portable and wearable electronic devices.