Corsair re-brands their PSUs, they don't make them. Corsair has a good track record on PSUs, they use quality PSUs made from quality PSU makers including Seasonic. Seasonic is an actual manufacturer of PSUs. Seasonic makes a lot of PSUs for other brands. Their own brand is self-titled, "Seasonic" and is so far only made up of quality products. To put it simply: If you buy a Seasonic branded PSU you know you are getting quality. However, like bardacuda said above many Corsair PSUs are functionally identical to Seasonic PSUs since Seasonic makes them so generally-speaking both are excellent PSU brands.