Help, I'm clueless. Is this safe to use??

Andrea • Rainbow baby born 2/1/17
Does anyone have any experience with this? It was given to me at my shower yesterday, I would like to use it if it's safe. I have read several things about not adding after market pads to your car seats. It looks like it can be used in a storoller as well though. Help I'm clueless and I don't like returning unless nesasary, especially if it's a gift.