These toroids are a good option to use for QRP/low power EFHW antennas, common mode chokes and baluns.  They are a bit more efficient on higer bands for an EFHW antenna.  Please do not use them below 6mhz.
 
For EFHW antennas we would not suggest more than 10w maximum SSB and therefore <5w data.
 
Recommended for use with the DG1JAN UniBalun available from this shop.