There is a problem with these products. The top (dusting mechanism) keeps popping off its mount making it very difficult to hand hold the bottle for routine dusting of photographic slides. The previously-stocked NXT similar (and larger capacity) products never had this problem.
Support people from the store were extremely helpful in finding the desired “Air Duster” and then applying it appropriately to the computer. By the time we got home the “stuck letter” had become usable again!