Package Content:
M3 x 4mm ---- 30pcs -- Full thread,
M3 x 6mm---- 30pcs -- Full thread,
M3 x 8mm---- 30pcs -- Full thread,
M3 x 10mm---- 30pcs -- Full thread,
M3 x 12mm---- 30pcs -- Full thread,
M3 x 16mm---- 30pcs -- Full thread,
M3 x 20mm---- 30pcs -- Full thread,
M3 Hex Nuts --- 150pcs.

About Countersunk Screws:
A countersunk screw is a type of fastening that sits flush with the surface of the material it occupies.
These screws typically are used so that you can cover them easily with either a screw cap or piece of wood.
Other applications include the need for a fastening not to protrude so other objects can rest upon it stably, or to fasten it further to another object.