Buy Barska 2 Questions About Paintball Scopes?

2 questions about paintball scopes? - buy barska

I bought a shuffle Barska area (here is the link: http://www.barska.com/ac10008.html) and I wanted them 2 questions:
1 - Is it okay to play paintball, without covering the lens? Custom ball damage to the lens?
2 - Is there a good type of lens cap that fits you best?
This is a 3-12x40 Barska scope (it is quite large prey, about 30 cm)