skull crushers are not for triceps…not if done properly. I’m not big on the names of the muscles but if you do it properly you hardly bend at the elbow (meat heads like to see more weight in their hands and tend to bend the elbow because its easier to do more weight.) You work below the armpit on that stuff there. I am the biggest fan of bench (especially dumbell and all verts, with decline being the most akward for me at the time.)