diff --git a/ethosu/vela/architecture_features.py b/ethosu/vela/architecture_features.py
index 04c1c62..b77205b 100644
--- a/ethosu/vela/architecture_features.py
+++ b/ethosu/vela/architecture_features.py
@@ -25,16 +25,15 @@
 from .ethos_u55_regs.ethos_u55_regs import resampling_mode
 from .numeric_util import round_up
 from .numeric_util import round_up_divide
+from .operation import Kernel
 from .operation import NpuBlockType
+from .operation import PointXYZ
 from .supported_operators import SupportedOperators
 from .tensor import MemArea
 from .tensor import MemType
 from .tensor import TensorFormat
 from .tensor import TensorPurpose
 
-PointXY = namedtuple("PointXY", "x y")
-PointXYZ = namedtuple("PointXYZ", "x y z")
-
 
 class Block:
     def __init__(self, w, h, d):
@@ -79,16 +78,6 @@
         return "<Rect: ({0},{1},{2}) ({3},{4},{5})>".format(self.x, self.y, self.z, self.x2, self.y2, self.z2)
 
 
-class Kernel:
-    def __init__(self, w, h, sx=1, sy=1, dx=1, dy=1):
-        assert sx > 0 and sy > 0
-        assert dx > 0 and dy > 0
-        self.width = w
-        self.height = h
-        self.stride = PointXY(sx, sy)
-        self.dilation = PointXY(dx, dy)
-
-
 class SHRAMElements:
     IFM8 = 0
     IFM16 = 1