This is an excellent brush to clean your bottles and is long enough to clean the litre bottles. These are sturdy and strong and will definitely fit into the opening of the Blue Glass Bottles. It is a good idea to soak your bottle first in Hydrogen Peroxide, White Vinegar or Grapefruit Seed Extract mixed with water. It is also a good idea to clean your bottle once per month. The length of the brush from end to end is about 17” including the round metal end. The brush area is 6” long. The diameter of the brush area is 2.5”.