Daiwa Soft Oval and Round Pearl Combo have the advantage of a soft, bait-like texture. This means that when a fish doesn't bite, it doesn't get suspicious and is much more likely to come back for more.
The round soft pearl can also be used as a stop between a sinker and a swivel, for example on a Texan or Carolina rig. It will then dampen the lead ball silently so as not to arouse the suspicion of the carnivorous fish you're after.