The 6402-20 single prisms from Seco are their premier prism system which incorporates a 62mm single prism with a stainless steel locking mechanism that’s easy to set while adjusting the prism and target tilt.
The heavy-duty silver-coated prism is sealed in a strong canister with an ‘O’ ring to prevent water and dust from getting inside.

The prism can be mounted in either 0 or -30 mm offset positions.