3 piece pack of temperature compensating springs from Horolovar (USA). .0021" thick (.053mm) x 5-3/8" long.Item will ship USPS first class mail and we can not guarantee delivery times. Our standard shipping for this item is USPS First Class Mail, which does not offer tracking number for shipment, and you have to understand we have no control over the speed of delivery via this way and will not be responsible for slow delivery. If you want to be able to have tracking number for item you have to upgrade shipping service to USPS ground advantage. Thank you