The learning of discriminative features is the key for fine-grained image recognition. To better extract effective features and improve the accuracy of fine-grained image recognition. we propose a two-level progressive attention convolutional network (TPA-CNN) for fine-grained image recognition. The model includes a multi-channel attention-fusion (MCAF) module and a cross-layer elemen... https://canadabrass.shop/product-category/scope-mount-systems/