Use model.component(<ctag>).mesh(<tag>).create(<ftag>,"Size") to specify element size properties in the sequence. Use 
model.component(<ctag>).mesh(<tag>).feature(<ftag>).create(<ftag1>,"Size") to specify element size properties for the feature 
<ftag> that can be any of the types 
Edge, 
FreeQuad, 
FreeTri, 
FreeTet, 
Map, or 
Sweep.
 
    Use model.component(<ctag>).mesh(<tag>).feature(<ftag>).selection() or 
model.component(<ctag>).mesh(<tag>).feature(<ftag>).feature(<ftag1>).selection() to specify the geometric entity selection. If you do not specify any selection the size feature is defined on all geometric entities. The selection is not available for the 
default size feature, tagged 
size.
 
    The property table specifies the physics for which the element size is calibrated.
 
    Hauto is a nonnegative scalar. This value is used to set several mesh parameters in order to get a mesh of desired size. Smaller values of 
hauto generate finer meshes with more elements. The integers between 1 and 9 has a special interpretation; they correspond to the mesh settings 
Normal, 
Fine, 
Coarse, and so forth in COMSOL Multiphysics. The value 5 correspond to 
Normal. When you set the property 
hauto, all other properties are set to their default value, according to the following tables (for 
table set to 
default). Other noninteger values provide mesh parameters that are interpolated from the values in the tables.
 
    The property hcurve is a real value that relates the mesh size to the curvature of the geometry boundaries. The Gaussian radius of curvature is multiplied by the 
hcurve factor to obtain the mesh size along the boundary. The specified 
hcurve is only used if 
hcurveactive is 
on, otherwise 
hcurve is taken from a preceding size feature in the sequence. In the default size feature, tagged 
size, 
hcurve is always active and there is no 
hcurveactive property.
 
    The property hgrad tells how fast the element size — measured as the length of the longest edge of the element — can grow from a region with small elements to a region with larger elements. If two elements lie one unit length apart, the difference in element size can be at most 
hgrad. The specified 
hgrad is only used if 
hgradactive is 
on, otherwise 
hgrad is taken from a preceding size feature in the sequence. In the default size feature, 
hgrad is always active and there is no 
hcurvegrad property.
 
    The hmax parameter controls the size of the elements in the mesh. The algorithm aims at creating a mesh where no element size exceeds 
hmax. The default 
hmax value is 
hmaxfact * 
maxdist, where 
maxdist is the longest axis parallel distance in the geometry. The specified 
hmax is only used if 
hmaxactive is 
on, otherwise 
hmax is taken from a preceding size feature in the sequence. In the default size feature, 
hmax is always active and there is no 
hmaxactive property.
 
    You can use hmin to control the minimum size of the elements. The main purpose of this parameter is to prevent the generation of many small elements near small curved parts of the geometry. The default 
hmin value is 
hminfact * 
maxdist, where 
maxdist is the longest axis parallel distance in the geometry. The specified 
hmin is only used if 
hminactive is 
on, otherwise 
hmin is taken from a preceding size feature in the sequence. In the default size feature, 
hmin is always active and there is no 
hminactive property.
 
    The hnarrow parameter controls the size of the elements in narrow regions. Increasing values of this property decrease the size of the elements in narrow regions. If the value of 
hnarrow is less than one, elements that are anisotropic in size might be generated in narrow regions. The specified 
hnarrow is only used if 
hnarrowactive is 
on, otherwise 
hnarrow is taken from a preceding size feature in the sequence. In the default size feature, 
hnarrow is always active and there is no 
hnarrowactive property.
 
    The values of hauto, 
hcurve, 
hgrad, 
hmax, 
hmin, and 
hnarrow are positive real scalars, or strings that evaluate to positive real scalars, given the evaluation context provided by 
model.param().