This Wind Deflector is precision machined, from 8mm thick smoked grey Perspex & 15mm thick black acrylic for the side support brackets. This is undoubtedly the best aftermarket wind deflector available for your Z4. Each side bracket is held to the cars roll bars with 3M VHB (very high bond) double sided tape & 2 stainless steel screws. The screen is in turn attached to the brackets with 6 small cap-head screws. Altogether, this provides a secure & safe attachment to your car. Everything is provided for a successful fitment to your Z4. A wind deflector reduces the amount of turbulence when driving with the roof down allowing for more comfortable driving. Perspex increases the poor visibility usually experienced with genuine mesh wind deflectors. Any logo or personalization of your choice can be laser engraved, at no extra charge.. Please let us know the logo you would like. There is an additional info box on the checkout page. Here you can advise us on your desired logo. Attachment hardware/brackets are included. Please see the note below. Easily installed in a few minutes. Can be left on with the roof up or down. THIS DOES NOT ATTACH TO THE OEM BMW SUPPORT BRACKETS. Our own precision machined support brackets are included. THIS IS FOR CARS WITH PLAIN ROLL BAR COVERS & THOSE WITH THE OEM BRACKETS REMOVED.