This is an original Microsoft 15v 4a, model 1536 and is identical to the picture shown, this model has the magnetic snap on connector to charge your 15v 4a tablet as well as a USB 2.0 port, that you can charge a whole host of different USB accessories you may own and with 15v 4a of power this Microsoft 1706 power supply can easily charge both devices.
 
Genuine Microsoft 15v 4a power supply charger specification: 
Power output: 15v 4a
Power input 100-240v
Connector type: Magnetic snap in connector
USB 2.0 connection: Yes 1x USB 2.0 port
USB Output: 5v 1a
Total power: 65w
Contents: Microsoft Surface Pro 4 65w charger & standard mains lead power cable.
Microsoft model: 1706
P/n: Ktc hu10042-15082

• Key points of the Genuine Microsoft 1706 power supply
• Fits Microsoft Surface Pro 4
• Free Mains power cable cord
• UK supplier with Uk stock
• USB 2.0 also on charging unit
• Original 65w Surface charger

A standard mains cable power lead cord is included with your Microsoft Surface Pro 4 power adapter, so you can charge your Surface tablet straight away. If you order from outside the UK we will send your countries correct power cord.

Also fits the Microsoft Surface Pro 3