I'd not really trust anyone to know much about tarantulas if they are referring to them by how many weeks they are. 4 weeks from when? From when they were 1i? 2i? Started eating on their own? Who the heck are you getting your spiders from? They sound incredibly uneducated.mine is about 1.5 inches but i had a sling that was apparently 4 weeks old and half the size and blue. this other place claimed this one is 8 to 10 months. here's some more pics
First one may have been mislabeled.just picked up a second P Metallica sling from a the 1st place I got mine from and talked to the owner and he couldn't believe that his employee said it was 4 weeks. He gave me the second sling because they was something wrong with the 1st one. The second one is also already blue. I also picked up a green bottle blue. It was a toss up between a GBB or a Blue Fang and went with the green bottle.