Since not all devices advertise a model type because the device has to support the ENTITY-MIB to do this. And it depends on the software version. How do you find out? I have several C2950 devices running IOS 12.1(19)EA1a and they are not reporting model in Detailed Device report.
Full ENTITY-MIB migration was not done until RME 4.1. In RME 4.1.1, I have a 2950 which is properly reporting model details in the RME Detailed Device Report:
Index Description Chassis Serial Number Chassis Vendor Type Chassis Model Name Physical Entity Name Slot Configuration Manufacturer Name Slot Capacity Free Slots Chassis Version Report Published Unique Device Identifier
1 Cisco Catalyst c2950 switch with 24 10/100 BaseTX ports FOC0824Y05C ws-c295024 WS-C2950-24 nms-dmz-2950-a 0 cisco 0 0 P0 false PID : nms-dmz-2950-a Cisco Catalyst c2950 switch with 24 10/100 BaseTX ports WS-C2950-24 VID : P0 SN : FOC0824Y05C