Roto Grip Clone Midweight. CLONE - "a thing that duplicates, imitates, or closely resembles another in appearance, function, performance or style.". And well, since the last version of this core part was unwillingly abducted, we felt it was our responsibility to the entire bowling galaxy to "clone" it and mix in a few upgrades & performance enhancing tweaks that bowlers of all skill levels on planet earth will benefit from.