The torque needed to remove a jar top varies from jar to jar and this must be taken into account. The universal mount subsystem has been given the task of grasping the jar itself. One of the problems with grasping the jar is that jars and jar tops come in different diameters. The universal mount must allow the customer to grasp a variety of jars of various sizes. Another problem is that jars and jar lids are made of different materials.
Some materials are more rigid and require more clamping force to grasp the jar.
In order to properly open a jar the clamping force must not impede the operation of twisting the jar top. In order to provide the customer with a functional jar opener certain requirements must be met. The jar opener must be simple in design with as few moving parts as possible. Fewer moving parts results in less room for failure of the product. The jar opener must be inexpensive for the customer.