I have a shed shackle and an 11mm chain with a closed shackle padlock to secure 3 bikes. I bought the shackle because I was worried about someone breaking into my shed which is hard to secure from the outside. My fears were realised when thieves attacked, however, due to fitting the shackle my three bikes inside were left untouched! They didn't even try to crop the shackle and just left empty handed! Really delighted with this product. It's easy to install and very well made. Thank you!