Using a charging cable that is not made by Apple harm iPhone?

There's no way anyone here can guarantee, whether or not, this "non-Apple" charging cable can damage your iPhone. Most likely, it will not. That is because your phone's charger is actually built into the phone and that's what controls the amount of current that it will accept from the power adapter via the "charging" cable.

You should, at least, verify that this cable is rated as a "charging" cable.

There is nothing inherent about a non-apple cable that will damage the iPhone. When it comes down to it, they are just wires with connectors on the end. Some things that could damage your iPhone or charger are:

• too thin of wire for charging
• poor wire connections
• shorted wires
• poor insulation on wires

If you are confident that the manufacturer makes quality products to avoid these issues, then there should be no problems.