FROM TICTOCPARTS -- PLEASE SEE OUR OTHER EBAY STORE ITEMS TOO! (Picture shown is an example of the spring; however, the exact brand is not necessarily what will be shipped.) Part # is Marshall Stock # Size options are via the pull down chart above and is for 1 spring unless you choose more. STEEL is the standard default listing ALLOY will be in description if available and typically are more expensive. Please check back, we continually add new product and sizes. If you do not see the size you are looking for, please let us know or if you are unsure, we have several reference manuals that can help find the correct mainspring for your watch - send us a note and we can confirm. Our items are NOS (New Old Stock) and we inspect EVERY item to make sure it is in good condition. However, if you are not completely satisfied for any reason, contact us within 30 days from date of purchase, and will make arrangements for return and replacing the item(s) or refund your purchase, less shipping, No questions asked (except how can we improve our service to you.)