You should consider the height and sound insulation that required from your site before you choose a proper model.
DF-65type suitable for Max height 4.2m, STC: 38DB to 43DB
DF-75type suitable for Max height 5m, STC: 30DB to 32DB(Frame Glass panel)
DF-85type suitable for Max height:6m,STC: 40dB to 53dB
DF-100type suitable for Max height:7m,STC: 48dB to 59dB
DF-125Type( Super-height) suitable for Max height:17m,STC: 40dB to 55Db