Stygian nymphs gave Perseus a pouch, winged sandals, and Hades' cap of invisibility. Hermes gave him
a sword. Athena provided a shield-mirror. Perseus needed the pouch to hold the head. He used the sword to cut while he looked into the mirror, which Athena may have held. He had to work backwards (mirror-image) to avoid accidentally meeting the death-ray eyes of Medusa. He then grabbed the head of Medusa by the hair as shown in this statue, still averting his eyes. The invisibility cap hid Perseus so he could escape pursuit by the two remaining, immortal Gorgon sisters, Stheno and Euryale, who woke up when Perseus slew their sister.
Source: "Perseus' Battle with the Gorgons," by Edward Phinney Jr. Transactions and Proceedings of the American Philological Association, Vol. 102, (1971), pp. 445-463
