These knob versions fit the Harbor Freight branded central machinery 6 ton ram release valve / screw with the rod going thru the release screw (KNOB #1). See picture #1 , #2 & #3. Pictures #4, #5 & #6 are of the other version of the knob that fits the T style release screw (KNOB #2). VIDEO: https://youtu.be/k0tdjR50Frg Please choose which of the release valve knobs you require, #1 or #2 in the variations drop down menu. These knobs are 3D printed from super tough ABS plastic. If you have any questions about this knob fitting your particular press jack, please convo me. DO NOT USE THIS KNOB ON ANY JACK / RAM RELEASE VALVE THAT IS USED FOR LIFTING. Why spend your money on Legacy Brand Coin Ring Tools? Customer Service & Support: Look at our 1000 + reviews here on Etsy & see what others are saying: “the folks at Legacy Brand Coin Ring Tools are very supportive & communicate so well regarding any questions you might have. They have made every effort to work with me in any way that they could. I have made several purchases from these folks & each transaction has been hassle free. I recommend them very highly. " “Love it, very timely delivery. Thank you Karen very much!! I only do business with Coin Ring Tools for all of my tools. Thanks Again! " “Received my items today. So very excited to use them. Delivery was great as I expected them later in the week. Everything in the package was well secured. Very happy with my purchase. Karen was fantastic & knowledgeable. She took the time to explain things well, answer all my questions, & provided great product photos & videos on how to use these items. Looking forward to some ring making! Highly recommend this shop " We don’t just make coin ring tools & sell them, we have our very own brand ambassador Gary Rosa. Gary is an expert coin ring & bell craftsman & he is available to help you figure out what Legacy Brand tools you need & how to make best use of those tools. Gary does all of our Legacy Brand Coin Ring Tools videos on YouTube, & has helped hundreds of customers get started in coin ring making. Here at Legacy Brand Coin Ring Tools, we strive to provide: Quality tools, made in the USA, & built to last. Fast order fulfillment & fast shipping from our centralized location in Abilene, Texas. Responsive customer service when you need it. Thank you for shopping with us & making Legacy Brand Coin Ring Tools a success. “Coin Ring Tools to Craft your Legacy” Karen & Larry Harnar Hydraulic Press Release Valve Knob | 6 Ton Press