Bohning Complete Tower Jig Kit The one base is Compatible with any of the arms. Comes with all 7 different pair of arms: Straight, 1 degree Offset, 3 degree helical, 1 degree right Offset, 2 degee right wing, 2 degree left wing Seven center posts: standard, pin nock, F nock, a nock, crossbow, swedged, & H.E. Nock Three rings: small, large & extra large Spacer plates Clamp release tape