This Ctrl icon is made in Material Design style developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 4,400 icons, all in the same style and quality.
This icon for control is a rectangle with sides that are nearly equal in length. The width is a bit larger than the height. The corners are rounded, and at its center are there letters ctrl, with the C being capitalized.