Pursuit XRs Ultra 2.8 

For the ultimate in speed, and good resolution on any instrument. We have designed the Pursuit XRs Ultra 2.8 around an optimized 2.8 μm particle and an advanced packing procedure. Now you can decrease your runtime while maintaining resolution. Lower back pressure allows high flow rates to be used, and the 2.8 μm particles of ultra-pure silica delivers 10-15% higher efficiency than 3 μm columns.