diff --git a/src/aero_particle.F90 b/src/aero_particle.F90
index e87c1041..ea00442b 100644
--- a/src/aero_particle.F90
+++ b/src/aero_particle.F90
@@ -570,4 +570,75 @@ subroutine f_aero_particle_refract_core( &
 
   end subroutine
 
+  subroutine f_aero_particle_set_weight_class( &
+      aero_particle_ptr_c, &
+      weight_class &
+    ) bind(C)
+
+    type(aero_particle_t), pointer :: aero_particle_ptr_f => null()
+    type(c_ptr), intent(in) :: aero_particle_ptr_c
+    integer(c_int), intent(in) :: weight_class
+
+    call c_f_pointer(aero_particle_ptr_c, aero_particle_ptr_f)
+
+    call aero_particle_set_weight(aero_particle_ptr_f, i_class=weight_class)
+
+  end subroutine
+
+  subroutine f_aero_particle_get_weight_class( &
+      aero_particle_ptr_c, &
+      weight_class &
+    ) bind(C)
+
+    type(aero_particle_t), pointer :: aero_particle_ptr_f => null()
+    type(c_ptr), intent(in) :: aero_particle_ptr_c
+    integer(c_int), intent(out) :: weight_class
+
+    call c_f_pointer(aero_particle_ptr_c, aero_particle_ptr_f)
+
+    weight_class = aero_particle_ptr_f%weight_class
+
+  end subroutine
+
+  subroutine f_aero_particle_set_weight_group( &
+      aero_particle_ptr_c, &
+      weight_group &
+    ) bind(C)
+
+    type(aero_particle_t), pointer :: aero_particle_ptr_f => null()
+    type(c_ptr), intent(in) :: aero_particle_ptr_c
+    integer(c_int), intent(in) :: weight_group
+
+    call c_f_pointer(aero_particle_ptr_c, aero_particle_ptr_f)
+
+    call aero_particle_set_weight(aero_particle_ptr_f, i_group=weight_group)
+
+  end subroutine
+
+  subroutine f_aero_particle_get_weight_group( &
+      aero_particle_ptr_c, &
+      weight_group &
+    ) bind(C)
+
+    type(aero_particle_t), pointer :: aero_particle_ptr_f => null()
+    type(c_ptr), intent(in) :: aero_particle_ptr_c
+    integer(c_int), intent(out) :: weight_group
+
+    call c_f_pointer(aero_particle_ptr_c, aero_particle_ptr_f)
+
+    weight_group = aero_particle_ptr_f%weight_group
+
+  end subroutine
+
+  subroutine f_aero_particle_new_id(aero_particle_ptr_c) bind(C)
+
+    type(aero_particle_t), pointer :: aero_particle_ptr_f => null()
+    type(c_ptr), intent(in) :: aero_particle_ptr_c
+
+    call c_f_pointer(aero_particle_ptr_c, aero_particle_ptr_f)
+
+    call aero_particle_new_id(aero_particle_ptr_f)
+
+  end subroutine
+
 end module
diff --git a/src/aero_particle.hpp b/src/aero_particle.hpp
index 7593dd58..3f7d176f 100644
--- a/src/aero_particle.hpp
+++ b/src/aero_particle.hpp
@@ -45,6 +45,11 @@ extern "C" void f_aero_particle_id(const void *aero_particle_ptr, int64_t *val)
 extern "C" void f_aero_particle_frozen(const void *aero_particle_ptr, int *val) noexcept;
 extern "C" void f_aero_particle_refract_shell(const void *aero_particle_ptr, std::complex<double> *val, const int *arr_size) noexcept;
 extern "C" void f_aero_particle_refract_core(const void *aero_particle_ptr, std::complex<double> *val, const int *arr_size) noexcept;
+extern "C" void f_aero_particle_set_weight_class(void *ptr, const int *weight_class) noexcept;
+extern "C" void f_aero_particle_get_weight_class(const void *ptr, int *weight_class) noexcept;
+extern "C" void f_aero_particle_set_weight_group(void *ptr, const int *weight_group) noexcept;
+extern "C" void f_aero_particle_get_weight_group(const void *ptr, int *weight_group) noexcept;
+extern "C" void f_aero_particle_new_id(void *ptr) noexcept;
 
 struct AeroParticle {
     PMCResource ptr;
@@ -408,4 +413,43 @@ struct AeroParticle {
         );
         return refract_core;
     }
+
+    static void set_weight_class(AeroParticle &self, const int weight_class) {
+        f_aero_particle_set_weight_class(
+            self.ptr.f_arg_non_const(),
+            &weight_class
+        );
+    }
+
+    static auto get_weight_class(const AeroParticle &self) {
+        int weight_class;
+
+        f_aero_particle_get_weight_class(
+            self.ptr.f_arg(),
+            &weight_class
+        );
+        return weight_class;
+    }
+
+    static void set_weight_group(AeroParticle &self, const int weight_group) {
+        f_aero_particle_set_weight_group(
+            self.ptr.f_arg_non_const(),
+            &weight_group
+        );
+    }
+
+    static auto get_weight_group(const AeroParticle &self) {
+        int weight_group;
+
+        f_aero_particle_get_weight_group(
+            self.ptr.f_arg(),
+            &weight_group
+        );
+        return weight_group;
+    }
+
+    static void new_id(AeroParticle &self) {
+
+        f_aero_particle_new_id(self.ptr.f_arg_non_const());
+    }
 };
diff --git a/src/pypartmc.cpp b/src/pypartmc.cpp
index c758a2a0..34f2d6dc 100644
--- a/src/pypartmc.cpp
+++ b/src/pypartmc.cpp
@@ -283,6 +283,11 @@ NB_MODULE(_PyPartMC, m) {
             "Reset an aero_particle to be zero.")
         .def("set_vols", AeroParticle::set_vols,
             "Set the aerosol particle volumes.")
+        .def_prop_rw("weight_group", AeroParticle::get_weight_group, AeroParticle::set_weight_group,
+            "Weighting function group number.")
+        .def_prop_rw("weight_class", AeroParticle::get_weight_class, AeroParticle::set_weight_class,
+            "Weighting function class number.")
+        .def("new_id", AeroParticle::new_id, "Assigns a new unique particle ID")
     ;
 
     nb::class_<AeroState>(m, "AeroState",
diff --git a/tests/test_aero_particle.py b/tests/test_aero_particle.py
index 02ea55b3..2a10799f 100644
--- a/tests/test_aero_particle.py
+++ b/tests/test_aero_particle.py
@@ -415,6 +415,26 @@ def test_set_vols():
         # assert
         assert sut.volumes == [3, 2, 1]
 
+    @staticmethod
+    def test_set_weighting():
+        # arrange
+        aero_data = ppmc.AeroData(aero_data_arg)
+        volumes = [1, 2, 3]
+        sut = ppmc.AeroParticle(aero_data, volumes)
+        aero_data = None
+        volumes = None
+        gc.collect()
+
+        # act
+        weight_class = 1
+        weight_group = 2
+        sut.weight_class = weight_class
+        sut.weight_group = weight_group
+
+        # assert
+        assert sut.weight_class == weight_class
+        assert sut.weight_group == weight_group
+
     @staticmethod
     def test_absorb_cross_sect():
         # arrange
@@ -490,6 +510,22 @@ def test_sources():
         assert len(sources) == aero_dist.n_mode
         assert isinstance(sources[0], int)
 
+    @staticmethod
+    def test_get_weighting():
+        # arrange
+        aero_data = ppmc.AeroData(AERO_DATA_CTOR_ARG_MINIMAL)
+        aero_dist = ppmc.AeroDist(aero_data, AERO_DIST_CTOR_ARG_MINIMAL)
+        aero_state = ppmc.AeroState(aero_data, *AERO_STATE_CTOR_ARG_MINIMAL)
+        _ = aero_state.dist_sample(aero_dist, 1.0, 0.0)
+        sut = aero_state.particle(0)
+        # act
+        weight_class = sut.weight_class
+        weight_group = sut.weight_group
+
+        # assert
+        assert weight_class > 0
+        assert weight_group > 0
+
     @staticmethod
     def test_least_create_time():
         # arrange
@@ -544,6 +580,19 @@ def test_id():
         assert min(ids) > 0
         assert len(np.unique(ids)) == len(aero_state)
 
+    @staticmethod
+    def test_new_id():
+        # arrange
+        aero_data = ppmc.AeroData(AERO_DATA_CTOR_ARG_MINIMAL)
+        sut = ppmc.AeroParticle(aero_data, [123])
+
+        # act
+        id_orig = sut.id
+        sut.new_id()
+
+        # assert
+        assert sut.id != id_orig
+
     @staticmethod
     def test_is_frozen():
         # arrange