Airsoft Tokyo Marui Tracer Unit (New Version). By far the best tracer unit on the market, along with the fact it's made in Japan by Marui! Will fit all Marui guns, and most other AEGs with its adapter, or over the flashhider. If it doesn't fit a certain model, it's likely able to fit with some simple modifications to the flash hider.. Uses 'tracer rounds' to light the sky up with the bad-boy. The internal system illuminates a very bright UV light as the gun fires (senses the motion of passing BBs), so the BBs are like fireworks! This thing is crazy awesome and highly recommended by our staff. This is the newest version of the tracer unit made by Marui.