They are all items children have climbed on to gain access to an open window. Children can fall from windows open 4 inches or more.
How can you protect your child from falls?
Keep Kids From Climbing Near Windows
For your crawlers and climbers, move chairs, cribs and other furniture away from windows to help prevent window falls.
Install Window Guards and Stops
Screens are meant to keep bugs out, not children in.
Install window stops to windows you want to open no more than four inches.
For windows you want to open more than 4 inches, properly install window guards to prevent window falls.