In the Titanfall games, jump kits are like small jetpacks; they help players gain thrust to make short leaps and can help decelerate during unexpected descents. When Redditor mcoractual made his Jack Cooper cosplay, he of course included the jump kit, as well as every other piece of the character’s gear. As you can see in the photo below, the costume has a lot of accoutrements. The jump kit in particular caught my eye because of its LED elements. The above image shows the lighting interior, while the below photo shows how it shines through the 3D printed casing.