I have this exact same sac. It is a good sac and I have had no issue's with it. I also bought an uber pump to go with it. Fills and empties fast. However, now I am ready to hard wire and plumb my boat so I don't have to hand fill the sacs. There are much better sacs out there if you are going to eventually plumb them in. Like this is top of the line for only a little more money. http://shop.maxwake.com/product.sc?categoryId=3&productId=30
You can hand fill this bag as well and then later you can hard wire it in without problem.
Spend the little extra money now and you won't have to do it twice. You will not be sorry.