A1-4 MKII Bluetooth PCBA - replacement part Sale! from 3500 /per Qty. Add to Cart This item is currently on backorder but you can still purchase it now and we'll ship as soon as more become available. A1-4 MKII Bluetooth PCBA and Antenna - This is for special order only - must have our approval before this item is ordered. - will ship via USPS - SKU: A1-4 Bluetooth PCBA + Antenna