A class 10 torpedo
The class 10 photon torpedo was a type of photon torpedo used by Intrepid-class starships.
Prior to engaging Species 8472 in 2374, with the assistance of the Borg, the crew of USS Voyager created several bio-molecular weapons, augmented with nanoprobes, including thirteen standard photon torpedoes and one class 10, armed with a high yield warhead. (VOY: "Scorpion, Part II")
Later that year, when Voyager encountered Terrasphere 8, Seven of Nine made Borg modifications to increase the ship's complement of nanoprobe enhanced torpedoes to include nineteen standard photon torpedoes and three class 10s armed with high-yield warheads. Upon learning this, Captain Kathryn Janeway wanted more modified torpedoes, but Seven warned her that they had depleted the supply of nanoprobes. Janeway urged her to find a way to make more, stating, "I don't intend to run out of firepower mid-battle." (VOY: "In the Flesh")