The 991 Vibration Sensor Mount (1/4″x28, 5/16″ hole, aluminum) was specifically designed for use with the 991 sensor. The mounting hole is 1/4 x 28 and will accommodate most sensors with such a mounting stud or screw. Clearance around the perimeter of the sensor mount may be a consideration for use. The mount is machined from aluminum stock and anodized. It has a smooth bore 5/16 hole for mounting directly to an existing location such as a case bolt, or the stud of a case bolt adapter. This mount is also used as the Allison T-56 engine accessory drive sensor mount with either 991V or 991D-1 sensors for conducting vibration surveys.