2: The new Dual Battery Tray will accept a pair of either Group 65 or Optima batteries. If you're using Optima batteries, you'll need to attach the supplied Optima Fit Kit because they're smaller than the Group 65. Installation simply requires using pop rivets to attach two special brackets to the bottom of the tray. If you wish, you can also use one Optima and one Group 65 by attaching only one of the brackets to the new tray. If you're using Group 65 batteries, instructions are given as to how to relocate the air-vent canister on the inner fenderwell to make room for the larger batteries.