The low profile FRW Series Power Resistors are a popular choice for power resistors where mounting  space is limited. Benefits of this series are:

Vertical or Horizontal mounting
Stackable option
Efficient heat distribution
Lighweight
Excellent mechanical rigidity and abilioty to withstand vibration
Overall high power to space ratio

Currently the FRW series is available in the following wattages:

20W
30W
50W
65W
75W

The standard tolerance is 5% for 50 ohms and above and 10% below 50 ohms. Custom tolerances down to 1% are available on request. Full data here