Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Good design but poor construction, wobbles a lot

This stock has a great design but the material it is made of is pretty cheap, after 2 games it starts to wobble a lot, it appears that the plastic is is made of starts to loosen in the joints, making it unstable and unfit to be used with a sling since it cannot support the weight of just the marker without the gas tank.