Arrow Lock E Series Satin Chromium Occupancy Indicator Deadbolt Auxiliary Lock with Interchangeable Core, 1-3/8" to 1-3/4" Door Thickness (Pack of 1) - Industrial Hardware - Amazon.com
Liphontcta Dock Indicator, Zinc Satin Nickel Bolt Door Lock Indicator Garden Sculpture Outdoor Decoration - Amazon.com
Indicator Deadbolt Modification - I Dig Hardware - Answers to your door, hardware, and code questions from Allegion's Lori Greene.
Schlage B571-625 Door Bolt Occupancy Indicator, Grade 2
Schlage B571-643E Door Bolt Occupancy Indicator, Grade 2
Restroom Occupancy Indicator Door Bolt, Schlage B571 - Doorware.com
DOITOOL 1set Bathroom Indicator Lock Door Bolt Occupancy Indicator Public Toilet Indicator Red Green Indicator Latches Red Accessories Green Accessories Toilet Door Indicator Locks Hinge - Amazon.com
Schlage B571-605 Door Bolt Occupancy Indicator, Grade 2
B571-622 Schlage Door Bolt with Occupancy Indicator in Black - Lock Depot Inc
Stainless Steel Restroom Door Bolt with Occupancy Indicator, AHI SIG267 - Doorware.com