It depends on what you need it for. Oglivy abd Mattes are good brands, however, they are on the more expensive size. As I mentioned, which half pad you purchase all depends on what it’s purpose will be. If your saddle fits well, I suggest not using one at all
My favorite half pads to use are Ogilvy, Equifit, and Thinline! Personally, I use ogilvy in practice with a ultra Thinline pad under my saddle pad directly under my saddle. It has helped a lot! The saddle fit plays a big role because of how it fits and how a half pad can accommodate your fit.