I am purchasing 2 xr's with sportmaster lowers. Can someone tell me how I can identify and verify if they are -1 or -2. I am told that they are -2 but want to make sure. What am I looking for? Thx in advance.

Sportmasters only come standard or -2. Imco offers -1

Look at the top of a Sportmaster lower, thick is Standard, thin is -2

thanks