Pro Series by HHIP 8017-0102 Screwdriver Type Ball Plunger, M6 x 1.0 Body Material: 12L14 Steel. Ball Material: 302 Stainless Steel Smallest and lightest spring loaded device Side-load tolerant. Control LED end forces. Screwdriver installation Ball diameter is 3.5mm. L Dimension is 13mm Initial end force is 4.9 lbs. Final force is 14 lbs