Feature 1Fitment: This conversion seat supports 20 inches frames from 451 To 406 wheel sets, P8 changed to 451 wheel sets, P18 changed to 451 wheel sets, etc. 2Function: This extender can change the original V brake column position to the middle support position of the frame, making the overall appearance of the bike better. 3Strong Structure: Made of aluminum alloy, brake caliper extender has a good luster bright color, not easy to fade rust, strong and high strength. 4Excellent Workmanship: The extension seat is professionally manufactured and has excellent conversion performance, which is very suitable for those who like DIY bicycle transformation. 5Installation Tip: Before installation, please make sure your bike has a middle support mounting hole. Easy to install, it comes with screws and nuts.Item Type: ConversionSeatMaterial: Aluminum alloy .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Package List1 x ConversionSeat1 x Screw1 x Nut