Adaptable, lightweight & strong, & with the latest Quarq technology, SRAM Quarq ELSA 10R Power Meter 53/39 Tooth GXP Chainset packs a four-pronged punch to elevate bike & rider performance. The subatomic spider houses integrated electronics, a CR2032 battery, LED indicator & visible ANT+ ID. Power Balance captures left & right drive strokes. Omni Cal gives you a choice of chainrings with no compromise on accuracy. Exogram Hollow Carbon crank arms by SRAM reduce weight & increase performance. With lengths of 170 to 175mm, ELSA will take any athletes cycling to the next level.