Black lab Size

Question
I am currently considering adopting a black lab mix.  I am not sure what the other part is as he is entirely black with just a small tuft of white on his chest and he has a lankier look to him than some labs I see.  He has floppy ears and is a slightly longer in the body (I think) than most labs that I have seen as well. The shelter has told me that he is 9-10 months old. He weighs approximately 25-30 lbs.  I am wondering how big he will get?

Answer
If he really is 9-10 months old, he shouldn't grow much more.  One thing is to check the ends of his forelegs.  If they are quite knobby as compared to an adult, the growth plates are still open and he has more growing to do.  

Many Lab mixes are very Lab looking.  Most people didn't know the Lab Golden I had 4 years ago was a cross unless I told them.  A few exceptions I can think of are a Lab/Border Collie that looked just like a Lab except the color pattern of the BC.  I have seen a Lab/Basset Hound whose body looked like a Lab, but had the short, crocked legs of the Basset.