James grinned pretty broadly, an easy sort of smile. "Cannon? Now you're speaking my language," he drawled. "As long as I don't blow my own head off, that could be interesting." But the arm was sturdy - it could withstand upgrades being done to it, could withstand bullets and blades and probably even maintaining a cannon blast. It was made of tough stuff, and so was he.
And regarding that. "It's mostly titanium alloy," he added, referring to Mikaela's question. Probably a mix with steel too, if he had to guess. "On the exo-armor coating here." Strong, light, durable - plus, it was relatively easy to secure on him when he did need to take the arm off for some reason. "But let's see this cannon - you feel like showing off, Wheelie?"