Quality of materials used is good. But, the design itself is faulty. The locking mechanism is screw type. So it has to be maneuvered in the exact position, while doing this, there is a rubber ring below, which almost always falls off, then the jar wont sit properly or lock in position. So when you are in a hurry, you tend to just start it, that in turn damages the plastic drive which is at the back of each jar. And that also damages the same drive which is in the main base where the jar fits the motor. Then due to improper fitting it affects the inside cutting blades which get jammed again and again and a person has to keep getting the plastic drive replaced in the jars and the main machine. Its quite frustrating. Pls understand properly the locking mechanism and then personally go in the market and check and buy another one which has a regular slot locking mechanism. This one is a total write off. Dont waste time repairing it.