An "unconditional guarantee" means a promise or assurance that has no conditions or requirements attached. It suggests that something will definitely happen or be provided, no matter what. Full definition
And not only that, but I'm also going to give you a second unconditional guarantee for 100 % of your money back. (secure.patriothealthalliance.com)
They offer a 100 % unconditional guarantee if you don't think this is the best oil for you. (geekwrapped.com)
Wesley argues that, from the gospel's point of view, there is no absolute right or unconditional guarantee of sexual fulfillment for Christians. (rachelheldevans.com)