H everyone! I was recently given a tag-a-long child's attachment for my bike but it is missing one of the attachment pieces....I believe it's called a "receiver"? Is that right? It has the pin and long arm but I guess I need a hitch and/or am receiver? I'm new to biking but love it and want to do a charity for my friend with cancer....I wish I could show someone wha I have so it would be more clear...I,ll get it straightened out..thanks for any advice!