Menus are sometimes hierarchically organized, allowing navigation through different levels of the menu structure. Selecting a menu entry with an arrow will expand it, showing a second menu (the sub-menu) with options related to the selected entry.
Torsion springs are normally mounted horizontally above the opening of your garage door. When you pull the door down, cables attached to the bottom corners actually force the springs to wind up, in turn energizing the system.
Side-mounted springs: These springs are long and heavy and mount to each side of the upper garage door track. They are like torsion springs, but instead use pulleys to create tension when the door closes.