The DT/DR-AiphoneAX2-SFP is a 2-channel Aiphone AX compatible fiber optic transmission system with two 10-bit video channels and two bi-directional Audio and four bi-directional contact closures using the industry standard small form pluggable (SFP) optical device. These contact closure channels can be individually configured as either normally open (NO) or normally closed (NC). The DT/DR-AiphoneAX2-SFP accepts PAL, SECAM, or NTSC formats. This product incorporates the industry standard Small Form Pluggable (SFP) optical device. This SFP gives you the option for either single mode, multimode or CWDM wavelength selections by simply plugging in the appropriate SFP module.