The Prism sharpener will fit any pencil with < 8.5mm in diameter.
If you want guaranteed superior sharpening results, we highly recommend our Fleek Dash pencils (launching soon). Alternatively, we tested Prism with Sharpie Peel-Off China Markers, which also work well.
Since we cannot control the quality of other pencils on the market, we cannot guarantee Prism will work well for all pencils out there.