The AdirPro Single Prism Traverse Kit 2159-01 is an essential package for precise backsight surveying applications. Its silver coated canister protects the 62mm diameter prism which has <5 arc seconds accuracy. The tilt target can be reversed and adjusted to 0 and -30 millimeter offsets. Attached is the optical plummet which is ideal to see the down point. This kit includes a 360 degree rotating tribrach adapter that can be mounted on prism poles with a 1-inch base. The optical plummet features a 2.5x twist focus and an adjustable plate vial. There is also a tribrach with an 8-minute circular vial and 5/8 x 11 threading. You have the option to purchase this kit with or without the prism. The Single Prism Traverse Kit comes with a carrying case and a 1 year limited warranty.