(fencing) A tool used in electrical fencing to detect whether or not a weapon has struck an opponent, which connects to a fencer's weapon by a spool and body wire. It uses lights and seem to notify a hit, with different coloured lights for on concentrate on and off focus https://gabletoppak.com/the-growing-threat-of-marine-pollution-and-how-gabletop-cartons-offer-a-solution/