The U.S. Navy is testing a new variant of the MK 48 submarine-fired torpedo that’s more accurate, packs a bigger punch, and can engage targets at a longer range, Scout Warrior reports.

At 21 inches in diameter and weighing more than 3,500 pounds, the MK48 can target foes up to five miles away, speeding toward them at more than 28 knots. Lockheed Martin, the manufacturer of the torpedo, is set to deliver 250 MK 48’s in the next five years.

While many of the specific details surrounding the prototype torpedo are unavailable to the public, senior Navy leaders have publicly discussed the prototype in a general sense, Scout Warrior reports.

“There is prototyping going on for new versions of underwater weapons with significant underwater range and a wider variety of payloads. We are now coming up with effects that better enable us to provide a broader range of options for future commanders,” Rear Adm. Charles Richard, director of undersea warfare, told Scout Warrior in an interview.

Translated from military jargon, they’re testing a more versatile, more lethal torpedo. At a time when Russia and China are emerging as near-peers with the U.S. in their undersea military capabilities, the greater range, lethality and accuracy of the MK 48 will be a welcome addition to the U.S. Navy’s arsenal.

According to Scout Warrior, the new MK 48 will be the first upgrade to U.S. torpedoes since the MK 48 Mod 7 was put into service in 2006. The new variant will have an improved acoustic receiver, new guidance-and-control hardware, and improved memory and processing power for better performance against evolving threats.

The new MK 48 heavyweight torpedo is just one of the 20 upgrades Lockheed Martin supplies to the Navy every month, according to senior Lockheed official, Tom Jarvo.

“A heavyweight torpedo is unmatched in its ability to sink things,” Richard said about the 650-pound high-explosive warhead. “The Mk 48 is a unique capability in the fleet.”