Durable Material: Spring indexing plunger is made of high quality stainless steel, high hardness, rustproof, sturdy and durable. Easy to Use: Indexing plungers, when in use, pull the handle out and rotate it 90 degrees and release. Lock Spring Screw: Indexing plunger with spring, smooth rotation, solid and durable, long service life. Uses: Self-locking knob plunger can control the expansion and contraction of the pin by adjusting the handle, to achieve indexing, positioning, or stop limit. Fine Thread: M10, M12, M16, M20 threads available. Specification: Material: Stainless Steel Size Chart: Overall Length: M10: 51mm (2.01 inches) M12: 61mm (2.40 inches) M16: 77mm (3.03 inches) M20: 90mm (3.54 inches) Package Includes: 1 x Indexing Plunger Note: Please allow slight variations due to manual measurement and differences in display monitors.