What a fabulous piece of kit. I brought the tracer for a Halloween night game at Hilton Park. It fits in as a Silencer would fit and Lights up the fluorescent tracer rounds. Even on full auto it succeeds in lighting each and every ball providing a brilliant stream of fire. You can even see the tracer rounds as they bounce off your intended target. I would thourughly recommend this to anyone
I have bought this unit several months ago from another retailer (wasn't available at JD then). I was sceptical at first as to whether the ultra-short time that the BB is lit up through the unit would be enough to make it glow in the dark. I needn't have worried! Even at very high firing rates (I tested up to 120 rpm) the BBs shoot out fully lit during their whole period of flight. You can see how far they really go as well as the ricochets and little fragments landing over the fence in neighbours garden - gulp! There is a nice muzzle flash from the unit, too!
The device takes 4 AAA batteries - be careful how you put them in as 2 need to go in +side down and 2 +side up, diagonally offset from each other. There is a very tiny imprint of the + signs next to them - easily missed, even in good light! The batteries last forever, I use rechargeables, only had to recharge after 30 full cap magazines had gone through. The unit switches on/off via a button on the screwthread side. It switches off automatically in case you forget, which is very useful. It apppears robust, dropped it twice so far with no ill effects.
In summary: this device outperforms many much more expensive ones on the market. For the fun to be had here this is a no-brainer. Buy many!