Flat Head Thumb Screw, knurled Big Round Head Bolt, Finger Tighten Adjustment Screw M3M4M5M6M8M10-M4*25 (5 pcss)
M3/M4/M5/M6/M8 Carbon Steel Black Zinc High-Step Head Hand/Finger Tighten Thumb Screw - China Knurled Thumb Screw, Hand/Finger Turning Screw | Made-in-China.com