A needle that consists of two pieces: the first piece has a tip, a shaft, a spring and a bi-color indicator, and the second piece has two parallel hollow lumens one lumen is for fluid entrance and passage, and the other lumen configured to receive the first piece. When the hypodermic needle tip touches the skin or being inside a tissue the spring will be squeezed and the first piece will be situated backward in its primary position. When the tip of the needle just enters any cavity or any vessel the spring will be freed and pushes the first piece forward with the change of the color of the bicolored indicator.
