I'm having trouble figuring out all the numbers on the hardpoint section of the Ship Specs page.

Class 5: 6x S5-6x M3C ASA Turret (3)

I know that class 5 refers to the type of hardpoint, 6x refers to the quantity of that hardpoint, and that S5 refers to the size of the installed hardpoint. What I don't understand is the second 6x or the (3) at the end of the reference. Could anyone shed some light on this please?

(This example is from the Idris-M page)