1/2" too big?

I found a guy local to me who is selling a brand new 6 slot rat rack that uses the cement tubs. It has 1/2" hardware cloth on it. Ive heard mixed reviews about what size for ASFs, some say 1/2" is fine, some say they have had escapees. Looking for opinions.

NOt sure what the answer is.

But, keep in mind the hardware cloth is cheap. for 5 bucks you could you could just staple some 1/4 inch over the 1/2 inch if you need to.