The only reason it's not getting the 5 star as that the module holding the CO2 cartridges and the minipump slides into place and then attaches with a small screw. However, both components are threaded, so cross threading the inner part is very easy. Unfortunately now the whole thing rattles, so had to remove this small module and carry the pressure in my pocket. Looking for ways to fix it.
do NOT remove this small part and you should be just fine.
As to the bottle holder part, it is solid, and would recommend this accessory over any cheap ones you could fine on the net, properly engineered manufacture.