Universal Pen Adapter Set Compatible with Maker 4 3/Maker Explore Air 2/Air Explore 4 3/Explore/Venture Work with Sharpie BIC Crayola Sakura and More Pens Less Than 0.5" It was improved to be a better fit for Maker 3 Version and all machines with a roller bar in front; The calibration unit is now easier to insert and remove. If only the pen shaft is less than 0.5 inches, you may use almost all pens on the cutting machine now. No more limits on using more pens. Universal Design: this CRAVERLAND universal pen adapters make more pens work with the cutting machine, not limited to the only brand CRAVERLAND pen adapters are compatible with Cricut cutting machines: compatible with Cricut Venture,Maker 4 3 and Maker,Explore Air 2/Air,Explore 3 and Explore(NOT FOR ONE) Fit All Varieties of Pens:Replace the original pen adapter,and fit all pens with a shaft diameter less than 0.5 in,not for pencils and crayons.Work with infusible ink,ink,brush,fine liner,marker,oiled paint,detailing pen,gel,highlighter,glitter pens and much more pens Fits All Brands of Pens:Craverland pens adapter set is compatible with Sharpie,Bic,Crayola,Staedtler,Pilot,Sakura,Papermate,Pentel,Tombow and all kinds of brands of pens/markers Easy Installation:Remove the original pen adapter.Insert the universal one with a quick calibration and a test; once you're proficient, pens will not need the depth calibration.Just take a look then you will know the required depth Easy to Store: Small enough to organize in the device or in the organize box comes in this packet Package Includes:2 x Pen adapters set,2 x calibration units,an instruction and a gift organize box Improved Version: improved the calibration unit for easier use on Maker 3, making it fit for all machines whether the roller bar is in front Perfect Match: color creamy white to match the machine, fits snugly in the pen clamp Deviation May Exist: due to the product's versatility, there may be a little bit off-center in the drawing that can fix with a test before running a project