Fin Tector
Weight: 1.05g each
Aggressive, Two-Part SP, can be flipped for attack or "defense", or more accurately "lots of recoil and a little attack" and "just the recoil"
Can be oriented to cover or uncover the Base Clips, allowing four possible orientations, generally it is more practical to cover them if only to prevent disassembly.
Heavy recoil in attack mode which means despite being previously touted as the best Attack SP, they are more of a hindrance than anything else. They're also fragile when used for attack.
Attack Rings already serve to attack so SP focusing entirely on attack are redundant, you are better off using something that adds weight to the outer edge of the Beyblade (Cross Survivor, Twin Guard, Survivor Ring) or has good synergy with the AR (Upper Attack, Defense Ring) or good LAD.
Defense mode has very well rounded performance in that it is truly awful for Attack, Defense AND Stamina
Not a useful part.