diff --git a/requirements.txt b/requirements.txt
index 87eac85..5a97c1c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,6 +5,6 @@ pillow
 opencv-python
 PyYAML
 scipy
-segment_anything @ git+https://github.com/facebookresearch/segment-anything.git@dca509fe793f601edb92606367a655c15ac00fdf
+sam2 @ git+https://github.com/facebookresearch/sam2.git
 torch
 torchvision
diff --git a/src/multilabeller/SAM/sam.py b/src/multilabeller/SAM/sam.py
index f446d9d..d41d214 100644
--- a/src/multilabeller/SAM/sam.py
+++ b/src/multilabeller/SAM/sam.py
@@ -1,6 +1,7 @@
 import cv2
 import numpy as np
-from segment_anything import SamAutomaticMaskGenerator, sam_model_registry
+from sam2.build_sam import build_sam2
+from sam2.automatic_mask_generator import SAM2AutomaticMaskGenerator
 
 from src.multilabeller.SAM_contour import SAM_Contour
 
@@ -13,12 +14,11 @@ def __init__(self, config):
         self.contours = []
 
     def initialize(self, config):
-        model_type = config["model"]["name"]
+        model_config = config["model"]["config"]
         sam_checkpoint = config["model"]["file"]
         device = config["device"]
-        sam = sam_model_registry[model_type](checkpoint=sam_checkpoint)
-        sam.to(device=device)
-        self.mask_generator = SamAutomaticMaskGenerator(sam)
+        sam2 = build_sam2(model_config, sam_checkpoint, device=device)
+        self.mask_generator = SAM2AutomaticMaskGenerator(sam2)
 
     def apply(self, image_input):
         masks = self.mask_generator.generate(image_input)
diff --git a/src/multilabeller/config.yml b/src/multilabeller/config.yml
index 4e66d8a..dc9c961 100644
--- a/src/multilabeller/config.yml
+++ b/src/multilabeller/config.yml
@@ -30,8 +30,8 @@ left_mouse_click:
   linux: "<Double-Button-1>"
 
 SAM:
-  device: "cpu" # "cpu" or "cuda"
-  model: "vit_b" # vit_l; vit_b or vit_h
+  device: "cuda" # "cpu" or "cuda"
+  model: "sam2.1_hiera_small" # sam2.1_hiera_tiny; sam2.1_hiera_small; sam2.1_hiera_base_plus; sam2.1_hiera_large
 
 shortcuts:
   circle_mode: "b"
@@ -48,5 +48,5 @@ shortcuts:
 #TODO: It should work with any image size, but its not working. We'll check this out in the future
 #TODO: It works OK with a square dimension.
 image_viewer:
-  width: 400
-  height: 400
+  width: 1000
+  height: 1000
diff --git a/src/multilabeller/image_viewer_app/image_viewer_app.py b/src/multilabeller/image_viewer_app/image_viewer_app.py
index c08beb3..1a73ada 100644
--- a/src/multilabeller/image_viewer_app/image_viewer_app.py
+++ b/src/multilabeller/image_viewer_app/image_viewer_app.py
@@ -84,24 +84,30 @@ def initialize_SAM(self):
                 cuda_available
             ), "PyTorch is having trouble with CUDA. Please change device to 'cpu'"
 
-        if self.config["SAM"]["model"] == "vit_b":
-            SAM_model_filename = "sam_vit_b_01ec64.pth"
-        elif self.config["SAM"]["model"] == "vit_l":
-            SAM_model_filename = "sam_vit_l_0b3195.pth"
-        elif self.config["SAM"]["model"] == "vit_h":
-            SAM_model_filename = "sam_vit_h_4b8939.pth"
+        model_name = self.config["SAM"]["model"]
+        SAM2_MODELS = {
+            "sam2.1_hiera_tiny":      ("sam2.1_hiera_tiny.pt",      "configs/sam2.1/sam2.1_hiera_t.yaml"),
+            "sam2.1_hiera_small":     ("sam2.1_hiera_small.pt",     "configs/sam2.1/sam2.1_hiera_s.yaml"),
+            "sam2.1_hiera_base_plus": ("sam2.1_hiera_base_plus.pt", "configs/sam2.1/sam2.1_hiera_b+.yaml"),
+            "sam2.1_hiera_large":     ("sam2.1_hiera_large.pt",     "configs/sam2.1/sam2.1_hiera_l.yaml"),
+        }
+        assert model_name in SAM2_MODELS, (
+            f"Unknown SAM2 model '{model_name}'. "
+            f"Choose from: {list(SAM2_MODELS.keys())}"
+        )
+        SAM_model_filename, SAM_model_config = SAM2_MODELS[model_name]
         SAM_model_file = Path("SAM", SAM_model_filename)
 
         message = (
-            f"{os.path.basename(SAM_model_file)} not found at src/multilabeller/SAM folder."
+            f"{SAM_model_filename} not found at src/multilabeller/SAM folder."
             f"\nPlease download the model file at "
-            f"https://github.com/facebookresearch/segment-anything?tab=readme-ov-file#model-checkpoints"
+            f"https://github.com/facebookresearch/sam2?tab=readme-ov-file#model-checkpoints"
         )
         assert os.path.isfile(SAM_model_file), message
 
         SAM_config = {
             "device": self.config["SAM"]["device"],
-            "model": {"name": self.config["SAM"]["model"], "file": SAM_model_file},
+            "model": {"config": SAM_model_config, "file": SAM_model_file},
         }
 
         self.SAM = SegmentAnything(SAM_config)
diff --git a/src/multilabeller/test/h5read_test.py b/src/multilabeller/test/h5read_test.py
index 43aa1c9..01688f9 100644
--- a/src/multilabeller/test/h5read_test.py
+++ b/src/multilabeller/test/h5read_test.py
@@ -3,7 +3,7 @@
 from pathlib import Path
 
 # Path to .h5 file - Modify it accordingly
-h5_file = Path(r"output/aiaiaia.h5")
+h5_file = Path(r"..\test\output\train.h5")
 
 # Reading the .h5 file
 h5_dataset = h5py.File(h5_file, "r")