Thank you for viewing. The center screw can be opened with a precision flathead screwdriver. [Compatible Models] Suitable for cordless vacuum cleaner models such as Dyson SV10K, SV18, SV20, SV21, SV22, SV30, SV33, SV46, and slim type and Detect type cleaner heads such as 354531, 354531-02, 442897, 425995, 425995-02, 972417-01, 442798, and 442897. *The above is quoted from the product description at the time of purchase. Please make sure it is compatible with your model.