These applicator needles are to be used with Polyvance's PlastiFix kit. While it looks like a hypodermic needle, it's really much different. You see, while most hypodermic needles have the hole at the tip, the PlastiFix Applicator Needle has the hole on the side about 3/8 inches (9 mm) from the tip. The PlastiFix Liquid will run down to the end of the needle and form a drop. You can then "stab" the powder/liquid ball without clogging the hole. If you have lost your needles or the hole is clogged, this 2-pack of needles is just what you need.