This is a single 0.40mm needle, Round Liner type, Point Taper sharpening level and a needle with a textured surface that allows for more pigment to be introduced.
The PT cone needle has a double sharpening, which means that in addition to the usual sharpening, the tip of the needle itself is additionally sharpened at a different, more obtuse angle. This type of sharpening means that the PT needle is not as sharp as the LT needle, which allows for more accurate insertion into the skin. PT - Cone tip (2.5mm with double sharpening).
Round liner cartridges
Cartridges are designed to create contours and lines. The 0.40mm needle will also leave a larger pixel than the smaller 0.35mm needle.