Taking elements from a normal sluice and a geo sluice. goes from approx 6" wide to a 3.5" trough for optimal small stream water flow. The difference in that measurement created trays for rocks and dirt to hold the sluice in the stream. Piece one only needs to be printed once and in the updated design the receiving area is extended. All joints use 10mmx 2mm magnets. Sluice piece 2 can be printed more times for extra length. No supports needed. Use Gyroid infil 10-20%