Best abs workout

Sorry for poor quality. I do not know what these are called. I have a kettlebell and as I plank with my feet elevated on stairs I drag the kettlebell under me to other side of my body then switch hands and repeat. My back should be straighter and I should fight the rotation which will work your obliques. I like these for functional use. I do basic 3 x 10 . Hope someone has better luck and form than I did