$fn      = 100;
    translate([0, 0, 12]) rotate ([0,180,0]) bioflow_top() ;
    
    module bioflow_top() {
    union() {
      difference() { 
          
        // Main cube  
        translate([0,0,6]) cube([110, 163, 12], center = true); 

        // 45 degree corners
        translate([53,81,5])   rotate([0,0,45]) cube([15, 28, 30], center = true); 
        translate([53,-81,5])  rotate([0,0,45]) cube([28, 15, 30], center = true); 
        translate([-53,-81,5]) rotate([0,0,45]) cube([15, 28, 30], center = true); 
        translate([-53, 81,5]) rotate([0,0,45]) cube([28, 15, 30], center = true); 
       

        difference() {   
            
          // Wide cut + corners for top cover  
          translate([0,0,-2.5]) cube([103, 156, 10], center = true); 
          translate([50,76,5])  rotate([0,0,45]) cube([10, 28, 30], center = true); 
          translate([50,-76,5]) rotate([0,0,45]) cube([28, 10, 30], center = true); 
          translate([-50,-76,5])rotate([0,0,45]) cube([10, 28, 30], center = true); 
          translate([-50,76,5]) rotate([0,0,45]) cube([28, 10, 30], center = true); 
        }

        difference() {   
          // Threshold cut + corners  
          translate([0,0,9]) cube([103, 156, 10], center = true); 
          translate([50,76,5])  rotate([0,0,45]) cube([10, 28, 30], center = true); 
          translate([50,-76,5]) rotate([0,0,45]) cube([28, 10, 30], center = true); 
          translate([-50,-76,5])rotate([0,0,45]) cube([10, 28, 30], center = true); 
          translate([-50,76,5]) rotate([0,0,45]) cube([28, 10, 30], center = true); 
        }

        difference() { 
          
          // Small cut + corners  
          translate([0,0,4]) cube([97, 150, 10], center = true); 
          translate([47.75,74,5])  rotate([0,0,45]) cube([10, 28, 30], center = true); 
          translate([47.75,-74,5]) rotate([0,0,45]) cube([28, 10, 30], center = true); 
          translate([-47.75,-74,5])rotate([0,0,45]) cube([10, 28, 30], center = true); 
          translate([-47.75,74,5]) rotate([0,0,45]) cube([28, 10, 30], center = true); 
        }

      difference() {
        translate([51.5,0,6]) cube([8, 40, 18], center = true); 
        translate([53.5,24,6])   rotate([0,0,45]) cube([10, 15, 16], center = true); 
        translate([53.5,-24,6])  rotate([0,0,-45]) cube([10, 15, 16], center = true); 
        }    
      difference() {
        translate([0,-77.0,7]) cube([40, 8, 18], center = true); 
        translate([-24,-79.5,6])   rotate([0,0,45]) cube([10, 15, 16], center = true); 
        translate([24, -79.5,6])  rotate([0,0,-45]) cube([10, 15, 16], center = true); 
        }    
      }  
      difference() {
        translate([56.5,0,6]) cube([3.0, 44, 12], center = true); 
        translate([56,26,6])   rotate([0,0,45]) cube([10, 15, 14], center = true); 
        translate([56,-26,6])  rotate([0,0,-45]) cube([10, 15, 14], center = true); 
        translate([54,0,13.5])  rotate([0,-45,0]) cube([5, 33, 5], center = true); 
      }    
      difference() {
        translate([0,-83,6]) cube([44, 3.0, 12], center = true); 
        translate([-25.5,-82.5,6])   rotate([0,0,45]) cube([10, 15, 14], center = true); 
        translate([25.5,-82.5,6])  rotate([0,0,-45]) cube([10, 15, 14], center = true); 
        translate([0,-80,12.5])  rotate([-45,0,0]) cube([33, 5, 5], center = true); 
      }    
    }
  }