Description: Refills 1 lb. bottles in 1 minute or less so quick Works with all 20, 30, or 40 Pound 50,Cylinders With this adapter you are not able to overfill the smaller bottles it will only put in the tank as much as it can hold, you are also able to back fill into larger tank if you got in a situation where your larger tank runs dry Hook up the smaller cylinder with this adapter and it will equalize the pressure between the two tanks Great for Ice Fishermen, mountain men Outdoorsmen, and all Campers and power outages Specification: Material: solid brass Size: 6.2*3.5*3.5cm/2.44*1.38*1.38inch Package Includes: 1 Piece Propane Refill Adapter Note: 1.We provide clear pictures, measurements where possible. Please check as much as possible to make sure the item is the one that you need. 2.Please allow 0.5-1 inch difference due to manual measurement.(1 inch=2.54cm) 3.The color of the actual items may slightly different from the listing images due to different computer screen, thanks for your understanding. 4.To use Adaptor to Refill 1 LB. Cylinders from 20-40 LB. Tank 5.Always start with an EMPTY cylinder. 6.Before refilling, chill the smaller empty 1 LB. cylinder for 15-20 minutes in the fridge (for best fill). Have full larger tank at room temperature (never exceed 85 °F). 7.No Instructions Included.Professional Installation Is Highly Recommended!