PHYSIO REHAB EQUIPMENTS offers a span of test possibilities. Patient first threads a large coupler from one end of a rod to the other end & then progress to a smaller diameter. You can measure the effort with Stop-Watch. * Twisting motion; heal, evaluate & develop finger dexterity with this Finger Prehension device. Specifications;* Bolts: Four, fine threaded Stainless Steel 30 cm high Bolts, * Bolts Diameters: 10mm, 12mm, 15mm & 20mm diameter.* Nuts: Four, Hexagonal Brass nuts of different diameters.* Construction: Bolts are fitted on a heavy wooden block base.