People have long used smoke to help discourage unwanted insect attention, it is thought to interfere with the way insects such as mosquitoes, midges, and black flies navigate and locate nearby activity. As the cone slowly burns, it produces a visible smoke that subtly masks elements like carbon dioxide in the surrounding air, a substance commonly exhaled by humans and naturally detected by many flying insects. You can create a safe heat free way of creating smoke with these citronella scented coils. The tin contains 10 coils with a burn time of between 6 and 12 hours (wind and humidity affects the burn time) and a holder. You can sit the burning coil down on the ground or table top, or place it in the tin to catch the ash. As well as the smoke produced the coils release a fresh and smoky citrus fragrance, perfect for summer evening in the garden, or on camping adventures. Metal tin & 10 CoilsCoil material 59.9% Wood powder (pinewood 50% + fir wood 50%), 37% Mucosity wood powder, 0,1% Colorant and 3% Citronella oil.)Burn time 6-10 hours per coil (wind and humidity affects burn time)