Now that women are expected to see combat, the Army and Marine Corps are adjusting the sizes of their body armors to accommodate them.

One size fits all body armor won’t work across gender lines. In addition to being leaner and shorter than the average male, women simply have different anatomy. Lt. Gen. Michael Williamson explained to Congress that providing equipment that won’t fit or protect a service member is dangerous.

“Anybody who’s worn a piece of body armor knows that it’s inconvenient enough without being [unable] to appropriately size it,” Williamson said. “In the design of our new protective equipment, we’ve worked very hard as you look at both the torso, the hard armor protection, the extremities with the soft armor, and the sizing so that we can fit both women and smaller male soldiers appropriately.”

Ill-fitting armor impedes a service member’s mobility. According to Stars and Stripes, women forced to don body armor in the past often had trouble lifting their arms or raising their guns in the cumbersome garments. Obviously, an inability to move fast or aim accurately can spell disaster in a combat situation.

Williamson stated that the Army has already added eight new sizes to its stock of body armor. It hopes to amass 7,200 sets of the new armor. The Marine Corps is gunning for 3,800 sets.