The SW150 Mark II Holder fits via a SW150 Lens Adaptor that has been specifically designed for that particular ultra-wideangle lens (the adaptor is purchased separately from the filter holder). 

This adaptor allows the SW150 Filter Holder to attach to the Sigma 20mm f1.4 Art lens.

The adaptor consists of a front ring, a compression ring and a locking ring. When fitted, these form a collar that remains on the lens at all times.

£84.37excl. VAT