Engineers at the U.S. Army’s Picatinny Arsenal in New Jersey are developing an ambidextrous multi-purpose hand grenade, which is the military’s first new lethal hand grenade in more than 40 years.

The Enhanced Tactical Multi-Purpose (ET-MP) grenade will let soldiers set the grenade to fragmentation or concussive effect with the flip of a switch. The weapon is also designed for ambidextrous use so it can be both armed and thrown easily with either hand. Current grenades require a different arming procedure for left-handed users, according to the Army.

War Is Boring reports that the Army’s current M67 grenade was designed for right-handed soldiers, so left-handed troops are trained to flip the grenade upside and hold the safety lever down with their left thumb, while pulling out the ring with the opposite hand.

The Army is also touting the new grenade’s ability to provide both fragmentation and blast overpressure more effectively and safely. Blast overpressure refers to the impact of the grenade’s shock wave on body surfaces.

Defense expert Peter Quentin, a research fellow at the Royal United Services Institute (RUSI) in London, sees the ET-MP as an important addition to the Army’s arsenal. “What’s quite interesting is the objective they are trying to achieve with this, which is a discretionary weapons system,” he told FoxNews.com. “This is important because it is all about minimizing collateral damage and civilian casualties, ensuring the appropriate effect is easily achieved and simple concussion/fragmentation selection makes it more likely to employ appropriate force.”

The request for a multi-purpose grenade was received from service personnel in 2010 and research began almost immediately. Engineers have been working with the U.S. Army’s Infantry School, as well as active-duty soldiers and Marines, to find exactly what troops require in a grenade.

“Our warfighter lost the capability of using an alternate lethal hand grenade when the MK3A2 concussion grenade was taken out of service in 1975 due to an asbestos hazard, leaving the M67 fragmentation grenade,” explained Picatinny Arsenal, in a statement.

Engineers with the U.S. Army Armament Research, Development and Engineering Center (ARDEC) are working on the ET-MP, along with the Maneuver Center of Excellence at Fort Benning and the Army’s Project Manager for Close Combat Systems.

The weapon will give more flexibility to troops. “They are currently carrying one M67 grenade that provides lethal fragmentation effects,” said Jessica Perciballi, ARDEC Project Officer for ET-MP, U.S. Army, Grenades & Demolitions Division, in the statement. “With the new multi-purpose grenade, they can carry one ET-MP grenade and have the ability to choose either fragmentation or concussive effects desired for the situation.”

The ET-MP also has electronic fuze timing. “Detonation time can now be narrowed down into milliseconds, and until armed, the hand grenade will not be able to detonate,” said Matthew Hall, Grenades Tech Base Development Lead, in the Army’s statement.

RUSI’s Quentin, a former British Army officer who served as a liaison to the U.S. Marine Corps in Afghanistan, emphasized that grenades are unique weapons. “Any weapon system that you use has some sort of sighting device, but with a grenade you’re using your own judgment and skill to be precise, it’s one of the most dangerous weapon systems that you use,” he said. “If you fumble that in a trench, it’s not just you but all your comrades around you that are likely to be harmed by that.”

The Army’s Project Manager Close Combat Systems will get the ET-MP in Fiscal Year 2020.

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