A device for selectively protecting a needle includes an adapter holding the needle and a guard engaging the adapter for relative movement therebetween. Further, the device includes a means for guiding movement between the adapter and the guard. Structurally, the guiding means includes a “V” shaped slot in the guard and a radially-extending boss on the adapter. The boss is received in the slot to limit relative movement between the guard and the adapter. Specifically, in a first position of the device, the boss is in a first leg of the slot and the needle partially extends beyond the guard. In a second position, the boss is held at the apex of the slot and the needle fully extends beyond the guard. In a third position, the boss is in the second leg of the slot and the needle is retracted into the guard to protect the needle.