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 Tamron 15-30mm f2.8 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.
$132.30