Tuned Detent System.
This knife is an amazing flipper.
The blade shape is a departure for Sinkevich, as was the 456 - that one surprised me as it was a departure from the slim, pointy designs I had come to expect from Mr. Sinkevich.
Then I started following his blog and see all of the interesting things he is doing, including his knives that have the blade shape like the 427.
I think the most interesting thing for me was the TDS, cool knife.
Now to actually answer the OP - I would not expect this one until mid-summer. I don't have inside info, just knowing that they have recently put out a few LE's and now will have to be focusing on new product for 2017, and SHOT is right around the corner.
I am guessing mid to late summer.
best
mqqn