The first thing you need to pay attention to is the weight of the bag. Because it is too light in weight bag will fly off your shots. The best option - if the weight of the bag, at least a little closer to the weight of the person. The advantage of a bag which will not be rushing, is the fact that the projectile will not take up much space in a small apartment. In addition, the Wallpaper and plaster in the room will be better off.
The next important parameter is the stiffness of the bag. This criterion is necessary if you are going to knock joints of the hand, when you knock your bag (bag). Therefore, even in the sports shop primaries to the bag, apply it 2-3 "test" strike. But also the bag should not be too soft where your impact "drown." Firstly, this bag is not suitable for working off of blows, and second, it can easily turn the brush.
Next on the rankings is the filling of the bag. Usually bags stuffed with sand, wood dust, or rubber shavings. However, if the bag is Packed only with wood dust, then quickly he will be mats will be compacted on the bottom and soft on top. Of course, this problem can be solved independently, just tapping out the entire "inside" of the back shell and covered by layers of sand and Stipa, fill the bag. But still, the best option is a bag filled with rubber shavings. This material does not rot, does not age and not break down. True, he has a flaw: it easier. However, there is a simple solution: you just need to fill up inside the sand. On the other hand, these bags are more expensive.
Now about the material of the cover. This is usually soft PVC, vinyl or leather. Although vinyl and PVC are cheaper but these types of material to wear faster. Leather is much stronger and, according to some, looks more aesthetic. But vinyl is easier to wash.
Then pay attention to the mounting mechanism - some steel rings that go around the perimeter of the top edge of the bag. This is a reliable mount, but the uppercut bag can come off the hooks. Therefore, the hooks better pre-bend. Another type of fastener, rope fastening, which converge together and are secured to the ring. This type of fastening is only suitable for light bags. If you are going to hang a bag of 40 kg, the fastener in this case will not fit.
Choosing the height of the bag, it is necessary to proceed from the possibilities of height of the room in which you need the bag to hang. And also, what are you going to do with him. The best option will be high bags from 120 cm, because the shock can be applied at all levels. But if your bag will serve not so extreme, you can come and shell 60-80 cm