The Door Bull is a powerful barrier to keep your home, business, or classroom safe. It attaches easily to inward-opening doors, making it virtually impossible to force the door open. The Door Bull Stops Them! It's more robust and powerful. And it helps your door frame do its job, by distributing the force more evenly and at the appropriate angles. Do not settle for old-fashioned, ugly, oversized security bars for doors! Smart Strong: Our precision-engineered front door security latches are made from strong aircraft-grade aluminum. Investing in a high-strength interior portable door lock latch can give you and your family peace of mind Easy Installation: Our high-strength security locks for front door installs in minutes. Thoughtfully designed security doorstops are easy to use and efficiently provide additional security and peace of mind Patented Design: Our portable door lock is designed specifically for your security Rental Friendly: The Door Bull, with its easy installation, is ideal for renters and landlords, protecting without damaging or modifying most standard door frames. It also comes in various finishes to adapt and match your existing hardware