I have two of the units, and neither one came with any instructions. I did find some information on their web site which had a parts breakdown and assembly picture. I also found out extra springs can be purchased, they are small, pop out easy and very easy to loose. I love my both of my injectors they are extremely handy and easy to use. I think they are originally manufactured for something else, and re purposed for cooking. that don’t matter to me though.