Megaro Arm
Weight: 2.7g
Small size
Right Spin Only
Two molds, second is thicker due to reinforcement to address breakage issues
Flat faces produce a fair amount of recoil without providing worthwhile contact points for attack.
Despite the small size, the flat faces and slight protrusion past Wide Survivor result in excessive recoil for use in survival or spin stealing customizations.
No competitive use.
Weight: 15.3g
The most compact weight distribution of any weight disk.
It is worth noting that there is quite a broad range of weights for this Weight Disk, which one should be wary of.
The large corners of its shape result in some recoil when hit, though its compact weight distribution provides some protection against this.
Ten Heavy outclasses it slightly in all aspects of performance due to heavier weight, lower recoil, and Eight Heavy is marginally heavier, with a slightly less compact distribution making it a viable alternative.
Fairly competitive in Compacts and Traditional Upper Attack and a backup choice for Weight-Based Defense and Semi Flat Base Stamina Combos.
Weight: 6.5g
Right Spin Only (Built in Spin Gear)
Very low height allows it to get under things but lack of compatibility with an Heavy Metal Core removes any use for Traditional Upper Attack.
Limited recoil control due to light weight and poor grip.
Somewhat difficult to flower pattern.
Decent LAD means it can be used to some effect similarly to a Semi-Flat Base Stamina setup, though due to its aggression it makes better use of Wide Defense - a viable setup would be this and a Compact or smaller-sized Defensive AR.
While this is not that competitive a setup, it is able to outspin a surprising number of opponents and KO weaker combos, thus giving Flat Base some semblance of use.
Overall not a great part, but usable.
Overall
While Heavy is a decent weight disk, there are much better Beyblades that carry it. Megaro Arm is for collection only.