I don't think it's a true velocity stack, but it sure looks cool! It's got to be better than the stock air filter/cover! The fewer obstructions to the air intake, the better! It can also be rotated to whatever angle you like, and I think this would go really well with the copper pasta tin fuel tank!
A warning to those looking to mod their motorized bicycles:
Most, if not all, of the hacks and mods featured on this site were made by individual hobbyists. If you are new to working with 2-stroke bicycle engines, please by aware that there's a possibility that a mod featured on this site could seriously damage your engine. Please don't try any mod from this or any other site unless you fully understand what you are doing. The owner of this blog will not be held responsible for both material and bodily damage caused by performing a modification featured on this blog. Also remember that opening up your engine may void your warranty!