What is the weight of this wetsuit?
By weight do you mean how warm is it supposed to keep you? At 5mm, it's designed for semi-cold water. I bought it, and it was fine for 74 degree water, but not ideal. It's a cheaper make, and so it doesn't keep you as warm as other suits (the neoprene compresses easier, which makes you colder). Get a 7mm, or, better yet, try to find an on-sale BARE suit on LeisurePro (that's what I did the year after I bought this suit).
It's my wife's, but I would say it's as light as your average jumpsuit maybe lighter because it has materiel in certain parts to make it more maneuverable. She likes it a lot, although she had a little trouble with the first one she bought, because she swims in a chlorinated pool, and it was very harsh on the suit. If you really don't use it a lot, and wash it off before getting out of it after being in the pool, it should be fairly ok, if that's what you're using it for. She's an instructor, so she's in the suit 8 - 12 hr's a week. But she bought another one and she is really washing it down to try to get as much chlorine off it as possible.
If you really need the exact weight I can ask her to bring it home, and I'll see if I can get a weight on it for you.