Calvins 3x3x3 Twist Black Shape Mod Puzzle Cube by Eitan Twisty Toy Difficulty: Easy This is a 3x3x3 Cube with a twist, literally! The puzzle looks good but the center cap easily pops out so you might want to glue it down The sticker quality is pretty bad due to the curve pieces The movement of this puzzle is smooth but no corner cutting, so not for speed cube