Q:-- Hole-freeSafety?-- A: Yes,this is a Pressure Mounthed.You don't need screws screwed in your wall.Without damaging the wall.set up with no tools requires.In house. Q:--Can be removed quickly in case of an emergency.How does that work?-- A: Yes.wWhen an Emergency happened,you can easy adjust the "adjustment knobs" of four bolts.That will be sooner than remove screws(screws window bar) Q:--What is window guard material and size?-- A: ABS plastics + Paint Irons made.measure. A: Bar Spacing:7cm/2.75 inches,Conform Exceeds 4 inch recommended safety standard for child window bars; Bar Height:76cm/29.9inches;Bar Diameter:1cm/0.39Inch. Mounting Options: Horizontal or vertical installations. Q:--Is this sturdy enough to serve as a burglar/break or just baby safety bar?-- A: NO a burglar/break.measure. A: Need in house installtion.This bars are pretty sturdy, especially when installed correctly. Once bolted to the side of the windows it will prevent a risk for accidental falls for you baby and toddler also prevent your dog from running into the window. Urgent:1.can unloading the Window Guard out of the way,but need use the wrench.It may take as much time as the installation. 2.Used the child safety window Guards,need Check the stability of both Adjustive Bolts regularly. 3.Remember your adult supervision is always the most important safety measure.