The Apple 20 watt charger specifications:

• Model number: MHJA3AM/A
• Power output: 20 watts
• Input voltage: 100-240V AC
• Output voltage: 5V or 9V DC
• Output current: 3A or 2.22A
• Connector type: USB-C
• Dimensions: 28 x 28 x 18 mm
• Weight: 32 grams