in the episode "Nature Pants," it is seen as a net made of gold. However, in the episode "The Pink Purloiner," it is a more advanced net with silicon netting, titanium skeleton, and soft red grip handle. The newer Ol' Reliable also appeared in the episode "Best Day Ever."
In the episode "The Pink Purloiner," SpongeBob thinks Patrick stole Ol' Reliable. At the end of that episode, SpongeBob and Patrick finds out that SpongeBob left it on the bus every week, and then gives it to Patrick, thinking he was going to move, but Patrick stays as they both jellyfish with their new nets.