If you perform duct leakage testing on multi-family units or smaller homes, with only one HVAC unit, then 10 register covers should be enough to seal the whole system.  The "10 Pack" of our custom air vent covers comes with an equal number of custom plastic hooks AND malleable, vinyl coated hooks to attach them to the ceiling or wall registers.  Simply attach them to the registers, cinch the cord tight, and you're ready to run your Duct Blaster® or DucTester without all the wasted time and expense.  When you're done, stack them on top of one another and you're ready to go.  Sets are warrantied for a full year, but last many more - see the testimonials page for more details.

*Pole RAT™ (remote attachment tool) is sold separately and allows you to set and remove the register covers without having to lug a ladder around.

Check out the testimonials page and see what people are saying.