for name, param in  model.conv1.named_parameters():
    print(name, param.device)

results in:
cbr_unit.0.weight cuda:0
cbr_unit.0.bias cuda:0
cbr_unit.1.weight cuda:0
cbr_unit.1.bias cuda:0

I also looped over all named parameters of my model and they all seem to be on GPU 0