King Size filter. These fit most long Denicotea standard holders and ejectors 89mm or over. Silica gel with its highly porous structure reduces tar and nicotine from tobacco smoke to a high extent. By changing color from clear white to dark brown the effect is clearly shown, and it indicates when the filter has to be changed. Only the original Denicotea filter has the red cap! Denicotea filters intended for use in denicotea holders, not for use in tobacco pipes.