Technical data

  MUR820 MUR820   Unit
Peak repetitive reverse voltage: 200 600    Volts 
Average rectified forward current: 8   Amps 
Peak rectified forward current: 16 16    Amps 
Non-repetitive peak rectified forward current: 100 100    Amps 
Maximum reverse recovery time: 25-35 25-35, 50-60    ns 

For complete data, please read the datasheet. Different brands aren't 100% identical in performance. ON seems to be better than International Rectifier, the MUR860 type.

http://www.irf.com/product-info/datasheets/data/mur820.pdf

http://www.onsemi.com/pub/Collateral/MUR820-D.PDF