1. Round and smooth, polished smooth edge without burr2. Round opening Round wide mouth design, easy to reverse3. Sealed leak proof double sealing ring, sealing moisture-proofName:3D Filament Dryer Box+Humidity Temperature Colour:As Shown Material:PP5+Metal Package Contents: 1 * printer consumables drying barrel 4L 1 set * accessories 1 * thermo-hygrometerOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.