This is the first time I see black-colored Catalyst switches from Cisco. 3650 switches are elegant and remind me of the old Juniper EX4200 switches. They have 48 PoE Ethernet Gigabit interfaces and four 1G SFP ports for copper/fiber uplinks.
A Cisco Catalyst 3650 switch contains two Cisco stacking ports that sit on the rear panel.
When put in a stack and entered the stack master election, the switch that becomes the stack master will have a constant green ACTV LED. However, the switch that is put in Standby role will have a blinking green ACTV LED.