NEW American Brass Double End Clock Key - Choose A Size! This is a brand new American Brass Double End Key. These are American Sizes. We also carry Swiss Sizes in our store. The Sizes are as follows: #4/1 (3.2mm on the larger end and a #0 on the smaller end) #4/3 (3.2mm/#000) #4/5 (3.2mm/#00000) #5/1 (3.4mm/#0) #5/3 (3.4mm/#000) #5/5 (3.4mm/#00000) #6/1 (3.6mm/#0) #6/3 (3.6mm/#000) #6/4 (3.6mm/#0000) #6/5 (3.6mm/#00000) #7/1 (3.8mm/#0) #7/3 (3.8mm/#000) #7/5 (3.8mm/#00000) #8/1 (4.0mm/#0) #8/3 (4.0mm/#000) #8/5 (4.0mm/#00000) **If you are unsure of what size you need for your clock please measure the width of the winding shaft or post in millimeters (it's more accurate than inches). If you need help let us know.** Free shipping is within the United States only. We do combine purchases to save on shipping as long as they are made on the same day. Please email me for combined shipping rates on multiple items and allow 24 hours for us to send you a combined invoice with your total. We do ship worldwide and always TRY to ship the same day payment is received. Return Policy: Items must be returned in original condition or it will not be accepted. A refund of the purchase price will be given. Shipping is non-refundable unless the mistake is ours. Make sure you order the correct size on your items so you don't have to send them back or exchange them. We are more than willing to help you get what you need. Please call or email us with any concerns or questions before leaving feedback. We care about our customers and will work with you on any issue. If you refuse to communicate with us we will have to block you from buying from us again. Thank you.