Sandbag Training Workout Universal Fillers – Can be Filled with Either Sand or Water. Multiple Sizes – XXL, XL, Large, Medium, Small – Guaranteed not to Leak

It works well in that it will definitely hold water. It didn't leak for as long as I had the bags I ordered. It makes for a great workout. However, this rubbery material gives off a very strange, kind of chemical smell, which kind of reminds me of pee, but that's not exactly an accurate description. It's just the closest thing I could think of comparing the smell to. It's not quite as bad as a real urine smell, but I did find it offensive, and what is worse is that the smell clings to the material it sits on or near, especially fabric. I had to throw out the small wooden bin I stored it in, because I couldn't get the smell out, even after I washed it with baking soda.

High quality product that should last for a long time. Like the fact that there's a double stopper system to prevent leaks.My only complaint is the buying options. I wanted a set so I don't have to fill/refill depending on the exercise. So I bought the 20/60/80 pound set. That's a big jump up from 20 to 60 pounds. Why not sell a 20/40/60 set? Or 40/60/80? Or 20/40/60/80? Docking one star for not having better buying options.

You might consider using glass beads instead of sand. Sand doesn't shift and conform very well, making the sandbags hard if you are using these tubes against your body during a workout. I happened to have a 50 lb bag of reflective glass beads, which I used in the place of sand. The spherical beads flow much easier than irregular grains of sand, so it conforms to shapes very well. The 19" x 4" tube holds exactly 20 lbs of glass beads. (Unfortunately, much more expensive than sand.)

I use this with a sandbag that normally carries 50 lb sand. With water, it is about 30 lb. generally, I take it when I am traveling and I want to do either crossfit style workouts. Compared to sand, the water is even more unstable and moves during olympic type movements or sandbag specific movements (with sandbags, that instability is somewhat the point, so this partly makes up for the fact that water is lighter than sand.). At a hotel, I usually fill these in the bathtub on my first day, then empty it out the night before I leave and leave the cap off overnight and put a spoon in to get it started on drying overnight. No problems with leaking. Now, my sandbag and these bladders are just something I pack to go on a trip.

Performs its job very well, the 80 lb size fits into a 80 lb goruck bag perfectly ... went to the beach to fill the bag and it took a great deal of effort, almost 2 hours using a make shift cut up milk carton to create a funnel ... the one star I took was due to the nozzle ... it is designed to be pulled out to fill and recessed once complete ... the nozzle is very difficult to extend then contract ... but ideally it will be a 1 time event to fill the bags ... as well, at 80 60 and 20, I find the 20 not really usable, I believe a better weigh would have been 80 60 and 40 ...

I thought id only use water in a pinch and sand most of the time for its weight but nope. Water is plenty heavy, especially if you use a large pack and medium pack. I use these in a fitshit bag. Fits perfectly.

I had to fill this in my stationary tub in the basement, it is too large to fill in a kitchen or bathroom sink - and it was hard to open to fill it. (And no - I couldn't use a hose outside because it is winter and our hose was put away for the season).It has no handles; I'd imagine it'd be easier to use if it did, or if it were filled with sand instead of water.

I purchased the item for a non-conventional use. I wanted to have something heavier and more cost effective to practice my lifeguard rescue stroke.I figured the industrial grade vinyl would tolerate the pool water, and it device would seal well to keep the water out and the filler in. They are definitely tough and would be great for their intended use.

They are great, empty at will for light transport