Please check sizing and make sure it fits before ordering. Double check your letterbox and where the fittings would need to sit to check that you have space as some letterboxes are fitted different. Size Post Box Cage for Door: 39cm (H) x 32cm (L) x 16.5cm (W) 19.1cm including bracket. Ample space for a letter catcher ensuring all letters can be stored safely. Internal Post Box Cage Fitting Size: up to 28.5cm. Letter Box Cage No Screws: The Letter cage include a unique hook on the back meaning that no additional screws or fixings are required. Making it a perfect letterboxes for UPVC doors. Easy Installation: Letter box catcher can be installed easily within a couple of minutes with just a screwdriver needed then placing the between on the current door letterbox. Durable Iron Construction: Built with sturdy iron for long-lasting durability, this indoor letter box catcher can handle regular daily use and deter animals to securely hold your mail. How To Fit: (1) Remove the screws from the top of your letterbox on the inside. (2) Pull the internal letter box cover forward away from the door. (3) Slot the large hook on the back of the mail catcher in between the letter box cover and door. (4) Screw the letterbox back into place. Pet-Proof Design: Our post catcher dog proof cage will secure against all curious pets from accessing mail, chewing contents, or damaging the letterbox flap. Please check the images on the listing, which shows how to attach the cage and if it will be suitable for your door & letterbox