They use a 3M two sided tape...can be found in some hardware stores...
Cyanoacrylate adhesives sometimes known generically as instant glues or
superglues like Goat tuff will work...work well but can/will lift paint off if you ever try to remove the BowJax... use light heat from hair dryer to remove.
If you never plan on it coming off...the Gaot Tuff will make sure of that...
I have done some of mine that I knew I would never take off
Neil