Barrier Super Plus Fly Repellent 5 Litre. Barrier Super Plus Fly Repellent is a super strength, 100% natural formula that defies all blood-sucking and nuisance flies including midges, bots, horseflies, house, stable and black flies. Super Plus helps to soothe and calm the irritation caused by midge bites and stops the need to rub. Barrier Super Plus contains pure avocado, which is known to be high in vitamins A, D and E, to deep condition and nourish the skin. Free from all prohibited substances under current FEI and HRA rules.