The VAJRA-331 monitor is a durable handheld control monitor for fixed installation as well as trailer mounted unit. Monitors are generally used to protect flammable liquid storage tanks, loading racks, sea dykes and many other industrial applications. The monitor has a 3-inch (80 mm) bronze blue track. Vertical and horizontal rotation is through a corrosion-resistant bronze swivel joint with two rows of stainless steel bearings. The Vajra-331 monitor is UL listed.