Do I really need one of these?

Hi, I do really need one as a person who loves to cook, because the sink saddle mat can protect my Pots, Pans and Dishes. If you would like a bigger silicone mat 18”long, it is here: https://www.amazon.com/dp/B09TL8L9VG

Will this sink divider mat fold out flat?

Yes, LeighCee, that mat will flatten out. My disappointment was that the mat was not the length I needed on divider of my sink, the description was inaccurate. I hope I helped with your query.

I just bough a new Blanco double sink and the divider is narrow. Will this item conform? most of the other dividers I have seen are 1.75 inches.

Actually, when I bought it I knew it would cover most if not all the division of the sinks. yet, I am very happy wit the performance, and it keeps protected the area from scratches. I can't vouch that this will work for you, however, if you are no happy with the size you can return it, To keep it in place I wet the little buttons that come inside so that they stick to the sides of the divider. It is not an expensive item so I would suggest you try it. Good luck.