This Apple 45W MagSafe 2 Power Adapter was designed for the MacBook Air laptops including MacBook Air (13-inch, Early 2015–2017) and the MacBook Air (11-inch, Early 2015). It could be used with any Mac laptop with the MagSafe 2 adapter, but may not charge as optimally as power adapters with higher wattages.
Apple describes the power adapter:
“The 45W MagSafe 2 Power Adapter features a magnetic DC connector so if someone should trip over it, the cord disconnects harmlessly and your MacBook Air stays put safely. It also helps prevent fraying or weakening of the cables over time. In addition, the magnetic DC helps guide the plug into the system for a quick and secure connection.”
Further, “Designed to be the perfect traveling companion, the adapter has a clever design which allows the DC cable to be wound neatly around itself for easy cable storage.”
This particular 45W MagSafe 2 Power Adapter is an Apple OEM (Original Equipment Manufacturer) part. It ships in a cardboard box with black cardboard and clear plastic wraps instead of the white retail box.