Genuine Craftsman replacement part. Spool cap 121071108 covers the bottom of the line spool and prevents the spool from falling out of the spool housing. Spool cap 121071108 covers the bottom of the line spool and prevents the spool from falling out of the spool housing. Consult owners manual for proper part number identification and proper installation. Please refer to list for compatibility. Includes (1) 121071108 Spool Cover. Spool cap 121071108 covers the bottom of the line spool and prevents the spool from falling out of the spool housing. Spool cap 121071108 covers the bottom of the line spool and prevents the spool from falling out of the spool housing. Consult owners manual for proper part number identification and proper installation.