: While aluminum arms look great, they don't flex. A hard crash with aluminum arms typically results in bending the metal or snapping the much more expensive plastic chassis or bulkheads. The 3631X composite arms absorb the energy instead.
: Priced typically between $10 and $15 for a pair, they are highly cost-effective insurance against broken parts ending your day of driving. : While aluminum arms look great, they don't flex
Are you looking to buy a set of these arms, or are you trying to for a specific custom RC build? : While aluminum arms look great