For Pro 240 Grit Buffing Block, Ultra Gold, 20 Count by For Pro

Are these the yellow 240 grit shown in the picture? Or are they the white 100 grit as the title states?

Would this work to smooth out and buff diy acrylics? Some places file marks and brush blemishes i need to buff before painting or too coat. e

Would this grit be fine enough for baby nails?

How long does it take to be delivered?