---
description: Explore detailed documentation of block modules in Ultralytics, available for deep learning tasks. Contribute and improve the codebase!.
keywords: Ultralytics, YOLO, neural networks, block modules, DFL, Proto, HGStem, HGBlock, SPP, SPPF, C1, C2, C2f, C3, C3x, RepC3, C3TR, C3Ghost, GhostBottleneck, Bottleneck, BottleneckCSP, ResNetBlock, MaxSigmoidAttnBlock, ImagePoolingAttn, ContrastiveHead, RepBottleneck, RepCSP, RepNCSPELAN4, ADown, SPPELAN, Silence, CBLinear, CBFuse
---

# Reference for `ultralytics/nn/modules/block.py`

!!! note

    This file is available at [https://github.com/ultralytics/ultralytics/blob/main/ultralytics/nn/modules/block.py](https://github.com/ultralytics/ultralytics/blob/main/ultralytics/nn/modules/block.py). If you spot a problem please help fix it by [contributing](https://docs.ultralytics.com/help/contributing/) a [Pull Request](https://github.com/ultralytics/ultralytics/edit/main/ultralytics/nn/modules/block.py) 🛠️. Thank you 🙏!

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## ::: ultralytics.nn.modules.block.DFL

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## ::: ultralytics.nn.modules.block.Proto

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## ::: ultralytics.nn.modules.block.HGStem

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## ::: ultralytics.nn.modules.block.HGBlock

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## ::: ultralytics.nn.modules.block.SPP

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## ::: ultralytics.nn.modules.block.SPPF

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## ::: ultralytics.nn.modules.block.C1

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## ::: ultralytics.nn.modules.block.C2

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## ::: ultralytics.nn.modules.block.C2f

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## ::: ultralytics.nn.modules.block.C3

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## ::: ultralytics.nn.modules.block.C3x

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## ::: ultralytics.nn.modules.block.RepC3

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## ::: ultralytics.nn.modules.block.C3TR

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## ::: ultralytics.nn.modules.block.C3Ghost

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## ::: ultralytics.nn.modules.block.GhostBottleneck

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## ::: ultralytics.nn.modules.block.Bottleneck

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## ::: ultralytics.nn.modules.block.BottleneckCSP

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## ::: ultralytics.nn.modules.block.ResNetBlock

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## ::: ultralytics.nn.modules.block.ResNetLayer

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## ::: ultralytics.nn.modules.block.MaxSigmoidAttnBlock

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## ::: ultralytics.nn.modules.block.C2fAttn

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## ::: ultralytics.nn.modules.block.ImagePoolingAttn

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## ::: ultralytics.nn.modules.block.ContrastiveHead

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## ::: ultralytics.nn.modules.block.BNContrastiveHead

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## ::: ultralytics.nn.modules.block.RepBottleneck

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## ::: ultralytics.nn.modules.block.RepCSP

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## ::: ultralytics.nn.modules.block.RepNCSPELAN4

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## ::: ultralytics.nn.modules.block.ELAN1

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## ::: ultralytics.nn.modules.block.AConv

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## ::: ultralytics.nn.modules.block.ADown

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## ::: ultralytics.nn.modules.block.SPPELAN

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## ::: ultralytics.nn.modules.block.CBLinear

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## ::: ultralytics.nn.modules.block.CBFuse

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## ::: ultralytics.nn.modules.block.C3f

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## ::: ultralytics.nn.modules.block.C3k2

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## ::: ultralytics.nn.modules.block.C3k

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## ::: ultralytics.nn.modules.block.RepVGGDW

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## ::: ultralytics.nn.modules.block.CIB

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## ::: ultralytics.nn.modules.block.C2fCIB

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## ::: ultralytics.nn.modules.block.Attention

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## ::: ultralytics.nn.modules.block.PSABlock

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## ::: ultralytics.nn.modules.block.PSA

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## ::: ultralytics.nn.modules.block.C2PSA

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## ::: ultralytics.nn.modules.block.C2fPSA

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## ::: ultralytics.nn.modules.block.SCDown

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