Packaging
Aside from the mouse, one finds a charging cable, wireless dongle, side button covers, solid back cover, and quick start guide in the box. The button covers lacked the necessary screws on my unit, so they fell off immediately. I don't know whether one is supposed to remove the screws from the regular side buttons and put them on the button covers.
Weight
My scale shows around 88 g (+/- 1 g). I forgot to take out the wireless dongle for the picture, so the actual weight is 87 g with the honeycomb back cover installed. With the solid back cover, the weight goes up to 90 g. Without any back cover installed, the weight goes down to 82 g. Getting rid of the side-button covers barely reduces overall weight.
Cable
The MoshPit WHM-01 comes with a braided charging cable (USB Type-A to Type-C). As far as flexibility goes, it's quite decent actually, and not entirely terrible when using the mouse with the cable. That said, there is no anchor at the mouse-end of the cable, so it may come loose inadvertently during use. Its measured length is 1.55 m. The cable has a ferrite bead attached, which reduces signal noise.
Feet
The feet on the MoshPit WHM-01 are white-dyed PTFE (Teflon) feet. Glide is decent.