Without instructions, bottles were found to be leaking and bottle labels were soaked with the contents of the bottles. Had to play around with the UV laser to figure out the correct orientation of the batteries to get it working. I was trying to glue the plastic frame of a broken sunglass arm. Having no instructions, I had no idea how long to expose the item to UV light. Needless to say, the gluing process failed and the glue didn't stick. Wasted time and money. I will try again and come back if the second try fails.