The Chicago Pneumatic 1312101097 beltguard is the back beltguard for several different Chicago Pneumatic and Belair piston compressors. The back beltguard would be the fursest away from the pump when looking at the front of the air compressor.
This is an OEM part made by Chicago Pneumatic Air Compressors. The part number may be displayed in your parts manual as 1312-1010-97 or 1312-1010-97
1312101097 will fit the following Chicago Pneumatic reciprocating air compressors:
1312101097 beltguard will fit the following BelAir reciprocating air compressors:
Part #: 1312101101
Part #: 1312101102
Part #: 1312100611
Part #: 1312100167
Part #: RCP-C1330G