Seco 25mm Mini Prism System w/ Side Vile. A versatile prism system in a small package. The assembly features a 25mm copper-coated prism, for fog prevention, a tilting holder, with friction axis, zero or -30mm offset. Includes a 40-min adjustable circular side-mounted vile. Assembly can be mounted on a Prism pole or tribrach at three heights: 70mm, 100mm, 115mm, or can be hand-held using the plumb bob bracket or with S-hook for quick attachment to plumb bob.