Check the listing for details. 2X Thumbscrews M4x20mm Wing nut Knobs Grip Audio Camera TV Electronics Drill. Condition: New, Made in China. Listed at 4.41 USD. Check out my other items! 2 x Plastic Thumbscrew Knob Male Thumbscrew Knobs An ideal alternative to an ordinary nut or bolt, suitable where a small, discreet product is required or where space is confined. Low profile knurled thumbscrew knob suitable where fine adjustment is required. A B C D E Thread size Thread length (mm) 18 5.8 6.3 6.3 M4 20 Material: Duroplast Standard Colour: Black Finish: Gloss Thread Material: Zinc plated steel Suitable Applications: Office furniture Medical aids and equipment Industrial machinery Aerospace equipment Construction equipment Marine furniture Agricultural machinery Electronics enclosures Point of Sale Printing equipment Packaging and processing equipment Lighting equipment Audio equipment 164u.