Huion H610 Pro Digitising Tablet Pen cover

This is a cover for the Pen device that comes with Huion H610 Pro Digitising tablet. I transport mine around in a laptop bag and the Pen comes with no cover, the nib looks very sensitive and prone to breakage so this simple cover was born,

UPDATE2:
Have removed the ridge on the inside as it was marking the pen, still grips without it and is a nice smooth fit after cleaning the print, there should not be any marking now so just check for rough edges when you fit.

UPDATE1:
I've just upl