These are great mouse sized boxes for $3 each for holding blocks of mouse poison. They can be secured by using zip ties. I put large enough blocks of poison in them so they cant be gotten out thru the holes (like xt blocks or eatons blocks). THEY ARE THIN PLASTIC SO NOT CHILD AND PET SAFE FOR OUTSIDE USE. I use them mainly in kitchens or stock rooms. I am a pro and use a lot of these.