The SECO Right Angle or Penta Prism 4900-00 is used to measure 90 or 180 degree angles. This survey prism will help you set desired targets. The metal cover can be rotated to reveal the pentagonal prisms and can be rotated reversely to cover the prisms. It comes with a leather case and slot for plumb bob cord.
This penta prism comes with a 1 year warranty.