Packaging
Aside from the mouse, one finds a USB Type-C to Type-A charging cable, wireless dongle, wireless extender, warranty card, quick start guide, and set of replacement feet in the box.
Weight
My scale shows around 85 g (+/- 1 g), which is almost exactly in line with the weight cited by Fantech. Compared to the largely similar AQIRYS T.G.A., which does feature plenty of holes, the Helios XD3 V2 only weighs 9 g more, which is quite reasonable. While not particularly lightweight, the Helios XD3 V2 isn't heavy, either.
Cable
The Helios XD3 V2 comes with a regular braided charging cable (USB Type-A to Type-C). There is no anchor at the mouse-end of the cable, so the cable may come loose during use, though it is unlikely given how tight it sits. In terms of flexibility, it is rather stiff and ranks even below the charging cable of the Razer DeathAdder V2 Pro. Accordingly, using the Helios XD3 V2 in wired mode may feel rather restrictive. The cable is 1.80 m long.
The charging cable also functions as an extension cable if used in conjunction with the wireless extender. The wireless extender can be used to keep the distance between dongle and mouse as short as possible. A storage compartment for the dongle can be found on the underside of the mouse.
Feet
The feet on the Helios XD3 V2 are white-dyed pure PTFE (Teflon) feet with slightly rounded edges. They are of above average thickness and glide very well. Their size and shape is similar to but not identical with that of the Zowie S2 feet. The ring around the sensor ensures CPI stays consistent upon applying vertical pressure. A set of replacement mouse feet is included in the box.