From the Fluidamper site

Fluidampr products have a 90-day warranty from the date of purchase. This warranty covers manufacturer defects in material and workmanship.

From the ATI website

ATI warrants to the original retail purchaser that all of their products will be free from defects in material and workmanship for a period of 90 days from the date of purchase. ATI will repair or replace, at their option, any part, assembly, or portion, after ATI's examination discloses it to be defective. ATI must be contacted to discuss a possible solution to the problem before the return can be processed. ATI dampers that have been installed are not returnable. Dampers must have their SFI sticker intact. Repairs or problems should be directed to ATI. ATI dampers are honed to fit OEM crankshafts and may not fit aftermarket crankshafts.

TCI only 30 days..

TCI Automotive products are warranted to be free from defects in workmanship and materials for a period of 30 days from the date of purchase on racing equipment, and a period of 90 days from the date of purchase on street/strip equipment. In addition, TCI Automotive will not warrant any of the following: Any product that has been physically altered, improperly installed or maintained, used in improper applications or abused, made defective due to accident, neglect, or unauthorized repair, or if proper cooling and/or fluid levels have not been maintained.