This is a 2 ml.sample bottle of liquid Micro-Mark brand PSA (pressure sensitive adhesive) Canopy Glue. We think this is the best brand of canopy glue. Our 2 ml. sample bottle makes it easy to apply adhesive exactly where you want it, plus we know that in the model railroad hobby, only a small amount is ever needed so this size is perfect and will last a long time, eliminating the need to purchase a larger 4 ounce bottle. The following description was taken from the Micro-Mark website about this glue: A clear, water-thin adhesive that dries quickly and creates a strong bond on many surfaces but still allows for re-positioning later on if desired Ideal for use in model-making, miniature work, and other applications where precision is necessary Can be used to attach decals, small parts, and other objects to models, miniatures and dioramas (like scale people on a layout)