This is a bag of carburetor needle valves. Typically one of these is used in a carburetor. This valve is used to control the fuel level in a carburetor float bowl. The carburetor float controls its operation. The rubber tip is used to seal against a seat. Often these needles are included in a carburetor rebuilding kit. Many times they're sold with a seat ,sometimes called a needle and seat. The specific dimensions of this needle are needed to identify its application. Very often needles will fit a variety of carburetors. These appear to be brass with the rubber tip. Carburetors are and were used on millions of gasoline powered engines from lawnmowers to heavy equipment.

0574-62578130 is the phone number for Zhen zing Industry Developing in China. They manufacturer a variety of custom screws and fasteners. Contact them and they should be able to identify exactly what these are.

References:

Www.zxqm.net

Reason:
Another opinion was accepted instead.

This is a bag of carburetor needle valves. Typically one of these is used in a carburetor. This valve is used to control the fuel level in a carburetor float bowl. The carburetor float controls its operation. The rubber tip is used to seal against a seat. Often these needles are included in a carburetor rebuilding kit. Many times they're sold with a seat ,sometimes called a needle and seat. The specific dimensions of this needle are needed to identify its application. Very often needles will fit a variety of carburetors. These appear to be brass with the rubber tip. Carburetors are and were used on millions of gasoline powered engines from lawnmowers to heavy equipment.

References:

These would often be listed as a carburetor float needle or valve. Check out eBay number 252300994399