The 200 HDR-Images of various reflection-effects and studio settings are provided in the most widely used formats:

Light-Probe (Angular Map)
Spherical Map (Latitude-Longitude)
Vertical-Cross
Horizontal-Cross

Radiosity - and therefore the use of HDRIs is directly supported in most 3D-applications like 3dsmax 6, VizRender 2005, Viz 2005, Lightwave (version 6.0 and higher), Softimage|XSI, Maya & Mentalray, Bryce 6, Pixar RenderMan, Autodesk VIZ4, messiah:render (Arnold), InSight (Integra), 3ds-max & VRay, 3ds-max & Brazil r/s (Splutterfish), 3ds-max & finalRender (Cebas), Cinema4D Version 8.1, Vue5, Lightwork Render System and many more.

High-resolution HDRIs:

The 150 HDRIs of "version 1" of this collection are provided in the following resolutions - and are therefore also perfectly suited for background use.
Light-Probe - 2048x2048 Pixel
Light-Probe Small - 512x512 Pixel
Spherical Map - 2048x1024 Pixel
Vertical Cross - 1536x2048 Pixel
Horizontal Cross - 2048x1536 Pixel
Format: .hdr (RADIANCE Image Format) and .exr (Open EXR)

The 50 additional high resolution HDRIs are provided in the following formats/ resolutions:
Light-Probe - 2048x2048 Pixel
Spherical Map - 6000x3000 Pixel
Vertical Cross - 3000x4000 Pixel
Horizontal Cross - 4000x3000 Pixel

All HDRIs are license-free and can therefore be used without any additional cost in all* commercial productions.