$39.99 at the Mothership with an “A” review rating on Fakespot.
The adhesive backing on these strips is generally not very good, even ones claiming to be “Heavy Duty”. They may work on a wall, but if you mount them on a ceiling or hanging on any horizontal surface they are likely to fall pretty quickly. Plan on having to come up with some other source of adhesion.
clean the spot where they’re to be mounted with rubbing alcohol- mine have stayed up for 15 months.