For maximum security, the M230-DC Deadlocking Spring Latch locks automatically every time the door is closed.  For added security, the deadlocking spring latch head contains a free-spinning, stainless steel burglar proof plunger. With it's smaller size, it will fit most other places that the larger models may have some difficulty fitting into. If you are looking for a great way to protect yourself from break-ins, then look no further. With the M230-DC you don't have to worry about your lock being picked or bumped, because there is no keyway to pick or bump! And, being a mechanical lock, you don't have to worry about being locked out due to dead batteries. This lock is also perfect to replace the latch on your pool gate. Limit access to when only you or another responsible adult are present by only sharing the code with those select few. The M230-DC is ideal for families who have a loved one living with them who has either Alzheimer's or Autism. With its double combination feature (keypads on both sides of the door) you can rest assured that your loved one is not wandering off into danger.