Patented under the following numbers: 5,676,243
4,976,124- 4,658,479- 4,612,685- D302,280.
with others pending
©1985-2020 C.E. Sanders
Calslock™ mfg.
 
Thumbsquare™
Pierson, FL - Keaau, Hawaii - Corcoran, CA

Calslock Portable Door Lock since 1985

Redesigned 2011 -2014 - 2020  
  
Added Security - Deters one leaving room 

Small children - Dementia or Alzheimer