With the proven SRAM X-Dome technology, the XG-1299 Eagle 12-speed cassette is one of the most durable and stiff cassettes on the market. SRAM achieves this by milling the cassette from a block. This manufacturing technique also allows the weight to be kept extremely low even with durable steel pinions. Only the 52 sprocket is made of aluminum. The increased bandwidth compared to the Eagle cassettes with 10-50 teeth not only offers more reserves for extremely steep climbs. With the bandwidth increased to 520%, high-performance riders can ride a larger chainring without impairing the climbing abilities of the bike. As a result, the drive enables a higher top speed and the driver also uses the larger sprockets of the cassette, which are more efficient.