When completing my 2nd and 3rd axis adjustments on my CBE Vertex, I always use the Hamskea Third Axis Level. It is a very quick and easy tool to use for leveling your sight. First you insert the threaded rod with the nylon nut into the level, making sure you can see the pin head on each end above and below your scope. Attach the level to the side of your vertical sight bar. Also make sure there is no residue that would not allow it to sit flat on the block. The edge next to the bubble vial is the true side.