Finally going to use it but can't remember whether it's C1 or C2.

Is there any way to tell by looking at the hitch?

 

Some vehicle information would help.
Your bio list nothing.........year, model nodda

for a current '08 F150
You can tell by:
Build code option 535 on you window sticker
Having an actual 2" reciever mounted from the factory
Having a factory 7 pin trailer connector plug from the factory
Having a 72amp/hr heavy duty battery
and Having an upgraded radiator and an auxillery transmission cooler

C1 or C2 refers to class I or Class II, tow packages that would be available in like say a Focus.

 

Oops.

2000 F150 RWD SuperCab Small V8

 

If you have a factory installed hitch and 7 pin trailer plug you have the tow package.