Reddit reviews Window Alert Bird Stickers Silhouettes Glass Door Protection Save Birds, Black - by FMJI

Window alert - Because the birds can't see glass!Helps - Reduce your feathered friends accidents and prevents breakage.Effective - Doing a good job of keeping your furry flying friends from crashing into the picture windows!Simple operation - Easy to post to the window/door. Peel it off, stick it on, done!Occasion - It is a long-lasting self-adhesive vinyl film stickers that fit for patio sliding glass doors and windows. It will not adhesive residue on your windows.