0,5mm fin gap, are you sure Roscal?
Comparing with the picture below, it gives the impression of being less that that (only visualizing), and it also seems a remake of a previous block, showed before in this forum: 1A-SL.
Even the water trajectory seems to be consistent to the aforementioned version.
Data that i gathered from the manufacturer:
1A-HV4 = 58x58x15mm and 1,6lpm with a Eheim 1046.
Former model:
