Features:1. Limit conversion frequency: 20KHZ.2. Size: 72*55*18mm3. Mounting Hole Size: 64*47mm, diameter 3mm.Application:1. It can be used for signal isolation2. PLC signal level converting3. PNP/NPN signal to NPN signal4. signal level voltage converterPackage included:1 x 24V To 5V 4 Channel Optocoupler Isolation Board