The PERFECT gift for my father that is very difficult to find. He's going to love it!PROS:- Such a unique little gift- They may claim that the shrimp only last a couple of years, but from the reviews I have read they can last up to ten.- This was sent when weather was below freezing so I was very worried about the shimp. The package actually came with a warmer, so the shrimp would stay the perfect temperature.- All of the shrimp looked different, so you could tell them apart.- They were all very active which I was not expecting- It was so cool that the algae was sort of just floating around in separate little pieces when I opened it. I left it on my work desk and noticed a little green ball of algae at the bottom of the system the next morning. Overnight, the shrimp gathered all the pieces and somehow formed them into a ball.- Seriously, how cool is this?!?!CONS:- The price is a little steep and I would reaalllllyyy love to get a medium or large system for myself but am not willing to pay that much.- You don't know exactly what your system is going to look like or how many shrimp you are going to get (which was actually pretty fun for me - especially since I got the max number of fish expected.**UPDATE**My dad absolutely loved this gift! He was confused at first upon opening it since he wasn't sure exactly what it was. Once I explained the system to him and he saw the shrimp swimming around his face lit up!He called today to let me know just how much he enjoyed having it at his computer desk and reported that all four of his shrimp were doing well and were all very active.This gift was by far worth the money and I plan on purchasing from this company again for myself and others in the future.