A hole seal is disclosed including a cover having a body with an inner surface and an outer surface and an end portion attached to a first end of the body. The device receives and supports trailer jacks having various configurations so that one device may be used with a number of differently configured trailer jacks. The variable speed control portion is operable to control the motor in a variable speed mode wherein the motor is operated such that a speed of the motor can be selectively varied within a range between the fixed speed mode threshold speed and a maximum motor speed. Further, the film thickness of the silicon dioxide on the inner wall of the isolation groove is sufficiently increased compared with previous structures to prevent an increase in the substrate capacitance.