Apple 60w magsafe 2 power adapter, which was designed specifically for certain macbook models with retina displays:
apple 60w magsafe 2 power adapter – specifications
feature details
power output 60 watts
connector type magsafe 2 (thin, wide magnetic connector)
input voltage 100–240v ac, 50–60hz (compatible worldwide)
output voltage/current 16.5v ⎓ 3.65a
led indicator amber = charging, green = fully charged
cable included built-in magsafe 2 dc cable; ac wall plug or extension cable (sold separately)