The tag says S(L), indicating it's a size S for the left arm. Although it's specified for the left arm, it hasn't been molded yet, and there's no difference in the stitching, so it can be used on either arm. This is an SBD elbow sleeve, size S. *Please note that this is only one sleeve.* If you have any questions, please ask, and I will respond promptly. Comments that have been up for a while will be deleted. Thank you for looking.