Full Marks Solution Spray is a fast and effective, 10 minute treatment that kills head lice and eliminates eggs. It dosen't poison the lice like traditional head lice treatments, but rather causes them to dehydrate and die. A detector comb is also provided and can be used to remove these dead lice along with any eggs. When used according to the instructions, Full Marks Solution Spray will kill head lice and eliminate their eggs. Unlike traditional head lice treatments which poison the lice, Full Marks Solution Spray has a physical action on the lice causing them to dehydrate (lose water) and die. They can then be removed along with any eggs using the fine metal toothed Full Marks Removal Comb provided.Effective in one use, Clinically proven to kill head lice and eliminate eggs, Eliminates eggs, No traditional pesticides, Comb included, 3 treatmentsKills Head Lice.Clinically Proven.10 minute treatment.Eliminates Eggs.No Traditional Pesticides.Odourless.Comb Included.When used according to the instructions, Full Marks Solution Spray will kill head lice and eliminate their eggs. Unlike traditional head lice treatments which poison the lice, Full Marks Solution Spray has a physical action on the lice causing them to dehydrate (lose water) and die. They can then be removed along with any eggs using the fine metal toothed Full Marks Removal Comb provided.