This is a brass Volcano length nozzle. Volcano blocks use longer nozzles.
(This is not for use standard V6 or MK7, MK9, MK10 aluminum heater blocks.) Volcano blocks use longer nozzles.
If you'd like to print fine details and keep your volcano heater block, installed, the 0.4 mm Volcano nozzle is great. No need to change back to a standard heater block, to have finer details. Keep you volcano heater block in place, and just swap nozzles. Cheers!
We have always recommended that printing with a Volcano nozzle is best done at lower layer heights. Although, you 'can' increase your layer heights, our best advice is: to take the speed gains with increased flow. For larger bore nozzles, and maintain a fine to medium (0.10, 0.12, 0.15, and 0.20) layer heights. This keeps your walls smooth. Many think you need you should increase your layer height with a larger nozzle. You can, but then you loose aesthetics, and strength. You can gain more speed, but if you aren't happy with the print, you've missed the mark.
If you like print in spiral or vase mode (recommended for YouTube and decorations only), a larger bore nozzle will give your added strength in your part, and print in the same length of time.
For parts with infill, or solids, printing with a larger nozzle, will speed up your print times dramatically, with a penalty of resolution from the top view. The great part about this is, if you don't have very fine details in the print (example: A Helmet, and no fine text present), you can still get accurate and smooth walls, with much less print time.)
The reduced print times is attributed to the added material flow, not from an increase in the machine 'print speed.'
If you have questions, please ask us. :)