PSP Buss Pressor is a compressor optimized for group and master bus processing. It combines the sound of classic VCA compression with wide tuning capabilities. Extra controls allow you to adjust a side chain high pass filter or apply parallel compression. Features:• Sweepable sidechain filter• Tweakable auto-release• Wet and dry controls• Excellent sound at both subtle and extreme settings Requirements: PC• VST• Windows x32 or x64 (XP Service Pack 2, Vista or 7)• VST 2.4 compatible application• RTAS• Windows x32 or x64 (XP Service Pack 2, Vista or 7)• ProTools LE 8.0.0 or ProTools TDM 8.0.0 (or later)• AAX• Windows x32 or x64 (XP Service Pack 2, Vista or 7)• Pro Tools 10 or Pro Tools HD 10Mac (intel)• Audio Unit• Mac OSX 10.5 or later• 32 or 64-bit host application capable of running Audio Unit plug-ins with Cocoa view• VST• Mac OSX 10.5 or later• 32 or 64-bit VST 2.4 compatible host application• RTAS• Mac OSX 10.5 or later• ProTools LE 8.0.0 or ProTools TDM 8.0.0 (or later)• AAX• Mac OSX 10.7 or later• Pro Tools 10 or Pro Tools HD 10