Weber's Pleurobranch

Large purplish brown pleurobranch with white double rings on the mantle. Mantle with small rounded tubercles. The colour plate clearly shows the conspicuous double white rings on the mantle. The unique sand patterns were created by burying in the sand, which they do during day time. However, strangely, I found this one during day time. And not just one but 3 of them!
Pic#1 is a couple mating and at their back is a Seastar which helps to give an indication of their size, which is around 25 cm. Pic#2 is a separate individual