Are you building or adding to a permanently mounted reference system? The 1.5THR is made exactly for that purpose - establishing permanent target points on jigs, fixtures, tools, and machinery. Use 1/4" bolts through the two counterbored holes in the base to provide secure mounting. Then, two other 15/64th holes act as drill guides for placement of dowels. Once the 1.5THR is bolted down, use a 15/64ths drill through these guide holes into the substrate, ream to 1/4", and insert dowels for a permanent fix on the target's position.

A lid is included to keep out dust and dirt when not in use, held in place by two up-facing magnets on the top face of the nest. The lid overhangs the base slightly to aid in removal.