YHT Safety Hook Type B, Size 6, New with tags, set of 4. I have some extras after purchase, and they have been stored in a dark place. Material: Iron, with unichrome plating. Easy to attach and detach. Size is nominal diameter. Used for connecting chains and other places where removal is necessary. Working load: 40kgf Please refer to image 3 for the size. There is a URL on the product tag, so please take a look if you want to know more details. Packing will be in cushioning material, and anonymous shipping is planned. I am also selling other hardware, etc.