DZERO GXP ALUMINUM CRANK INFORMATION When youre looking for a cost-effective and super-durable choice for a -based power meter Quarq offers up this version, the DZero Aluminum . This model shares a spider with the Red and Carbon versions, just replaces the arms with forged aluminum . You save a bundle. The great thing is that the new DZero spider is the bees knees. Its the newest, most advanced spider Quarq has ever created. Theres so much going on here, though what really matters is that it does what its supposed to do better and more efficiently. That is, it measures power more consistently than ever before, still has a 1.5% accuracy, has better battery life, despite the fact that it now broadcasting both ANT+ and Bluetooth low energy (BTLE) all the time, and it still offers all the features ve come to expect from Quarq. That means you dont need to affix a magnet to the frame to turn it on, the 2032 coin cell battery is user-replaceable and available just about everywhere, there is power balance to measure right and left strokes, there is 10k temperature compensation to make sure the meter doesnt lose accuracy as the day warms up and cools down, it has OmniCal to make sure that you dont need to recalibrate when you change chainrings, and it has a waterproof rating of IPX7.