In a Dutch oven, combine cider and red hots. Stir in pectin. Bring to a full rolling boil over high heat, stirring constantly. Stir in sugar; return to a full rolling boil. Boil and stir 1 minute.
Remove from heat; skim off foam. Ladle hot mixture into six hot half-pint jars, leaving 1/4-in. headspace. Wipe rims. Center lids on jars; screw on bands until fingertip tight.
Place jars into canner with simmering water, ensuring that they are completely covered with water. Bring to a boil; process for 10 minutes. Remove jars and cool.
