This is a A-520K4 Micro-Rib V-Belt (52") PN: 520K4Main Description As Following : A-520K4 Micro-Rib V-Belt (52") P.N: 520K4 4 Rib X 52 K Micro Rib Polyester CordColor: BlackLength: 52Material: Polyester CordMetric Code: 4PK1321Number Of Ribs: 4Outside Length: 52.63"Pitch Length: 52"Thickness: 0.18Type: K Micro RibWidth: 4 Rib Crossed From: K040520 GATES , 25040520 , , 4PK1318 A & I METRIC BELTS , 4PK1319 A & I METRIC BELTS , 4PK1320 A & I METRIC BELTS , 4PK1321 A & I METRIC BELTS , 4PK1322 A & I METRIC BELTS , 4040520 GOODYEAR , 5040520 DAYCO Found in Section & Models : Industrial Belts > K-Poly Belt, (Miscellaneous) (UNDEFINED): SEVERAL Associated Items : New Also This is An Aftermarket Product And : 4 Rib X 52 K Micro Rib Polyester Cord Color: Black Length: 52 Material: Polyester Cord Metric Code: 4PK1321 Number Of Ribs: 4 Outside Length: 52.63" Pitch Length: 52" Thickness: 0.18 Type: K Micro Rib Width: 4 Rib