Abstract: A firearm measuring device for measuring all external dimensions of a firearm is comprised of an elongated rectangular caliper body member having measurement indicia inscribed thereon. A pair of jaws affixed on the caliper body member, one jaw affixed to a carriage and moveable along the caliper body member, a second jaw permanently affixed at one end of the caliper body member. A drop meter affixed to the caliper body member adjacent to the fixed jaw and vertically adjustable along the length of the drop meter by a channel within the length of the drop meter. The drop meter having a measurement indicia inscribed thereon. An extension member for attachment to the caliper body member having a bottom tooth-shaped configuration which is positioned on a gun barrel. The extension member having a magnetic means recessed within the extension member for securing the extension member in combination with the caliper body to the gun barrel eliminating need of holding the device during operation.

Abstract: The present invention provides a controller for an air compressor system. The air compressor system includes an air compressor, control unloaders on the air compressor to prevent the air compressor from compressing gases when signaled to unload, an electric motor for driving the air compressor, and a tank for receiving and storing compressed gases from the air compressor. The controller has an adjustable pressure switch to raise or lower the discharge pressure. The differential pressure is pre-set in the pressure switch. The controller includes two methods of operating the air compressor, each of which is manually selected by operating a switch that will designate start/stop control or automatic dual control at the option of the operator. The start/stop control will start the motor when the pressure in the system reaches a predetermined low point. When the preselected high pressure point is reached, a signal is sent to the motor to stop, thereby ending the compressing cycle.