[it's slightly heavier than an actual arm but probably not as heavy as Bucky thought it'd be]

We ran like twenty different simulations, JARVIS said it'd be fine. [waves at the room before JARVIS says anything] Don't even start, JARVIS.

[and once it's all strapped in, the arm starts up. It makes a noise similar to Tony's suit when it's readying a shot. And also the tingling is more like mild electrocution, but it only lasts for a second, rly]