2.1mm to 2.5mm DC-to-DC Adapter $1.95 This adapter allows you to use a 5.5 x 2.1mm DC power supply for a device that requires a 5.5 x 2.5mm power supply. Many of Allo's older audio boards feature the larger 2.5mm size, but their newer boards (2020) and Audio Power Supplies are all the more... Add to Cart