Simple categories matching symmetrical:

• pattern,
• object,
• fashion,
• shape,
• product,
• motif,
• model,
• symbol,
• form,
• part,
• trait,
• curve,
• figure,
• animal,
• component,
• stocking,
• opening,
• block,
• solid,
• feature,
• surface,
• pearl,
• item,
• creature,
• unit,
• organism,
• structure,
• organs,
• container,

Members with property symmetrical:

• circle,
• envelope,
• hole,
• bulb_shape,
• sphere,
• rectangle,
• cylinder,
• square,
• flat_disc,
• concentric_circle,
• impeller,
• dog,
• shark,
• arrow,
• long_cylinder,
• polygon,
• fish_fin,
• brain,
• face,
• pipe,
• small_gear,
• crystal,
• mirror,
• dodecahedron,
• regular_hexahedron,
• bolt_hole,
• ball,
• bow,
• elongated_prism,
• book,
• stripe,
• fcc_cube,
• cube,
• virus_particle,
• whole_body,
• round_sphere,
• octahedron,
• truncated_cone,
• ctenophore,
• physical_system,
• cone,
• tetrahedron,
• nut,
• bolt,
• eyes,
• vehicle_member,
• optical_lense,
• triangle,
• apple,
• teardrop,
• turtle_deck,
• concentric_pattern,
• fish,
• radiation,
• band,
• painted_vase,
• person,
• broad_shoulder,
• cnidarian,
• drosophila,
• boat,
• cylindrical_cardboard,
• echinoderm,
• tweak_head,
• character,
• bookend,
• mollusc,
• axle,
• reflector,
• coelenterate,
• notebook,
• person_face,
• plane,
• star,
• ellipse,
• tails,
• character_face,
• trapezoid,
• spherical_sector,
• toy,
• rectangular_parallelepiped,
• zebra_stripe,
• disc,
• starfish,
• hexagonal_shape,
• mouse,
• tree_structure,
• ball_joint,
• piston,
• human,
• hemisphere,
• glass,
• round_disk,
• oblong_curve,
• perfect_circle,
• regular_octahedron,
• chair,
• bearing,
• legs,
• ngf,
• chicken,
• game_ball,
• cocktail,
• auto,
• clock,
• radial_pattern,
• disk-brake_disk,
• bird,
• annulus,
• tree,
• drop,
• torso,
• cap,
• furniture,
• button,
• ax,
• computer_equipment,
• island_model,
• drop_pearl,
• box,
• spheroid,
• shield,
• human_brain,
• heart,
• courthouse_steps,
• stovepipe,
• regular_dodecahedron,
• old-fashioned_camera,
• film,
• torus,
• plastic_elements,
• tube_sock,
• annelid,
• crayfish_great,
• isosceles_triangle,
• snowflake,
• large_chest,
• tubular_crystal,
• oval,
• shaft,
• pentagon,
• flower,
• model,
• hexagon,
• earthworm,
• animal_head,
• regular_polygon,
• octagon,
• parallelepiped,
• rectangular_object,
• virus_capsid,
• cylinder_shape,
• roller,
• closure,
• paper,
• arms,
• snowman,
• fish_fig,
• horizontal_stabilizer,
• trapezoidal_solid,
• metal,
• rosette,
• steps,
• cup,
• rounded_rectangle,
• jellyfish,
• tube,
• bottle,