This is a Cub Cadet front wheel cap 731-3020. It fits 

Cub Cadet GT2000 (14W-3DM-010, 14W-3DM-210) - Cub Cadet Garden Tractor (2011) - Front Axle Assembly 1 inch axle
Cub Cadet GT2000 (14W-3DM-010, 14W-3DM-210) - Cub Cadet Tractor (2013) - Front Axle Assembly
Cub Cadet GT2100 (14W-3AE-010) - Cub Cadet Garden Tractor (2011) - Front Axle Assembly 1 inch axle
Cub Cadet GT2544 (14A-2E7L010) - Cub Cadet Garden Tractor (2009 & After) - Front Axle
Cub Cadet GT2554 (14A-2A7K010) - Cub Cadet Garden Tractor (2009 & After) - Front Axle
Cub Cadet GTX2000 (14W-3FM-010, 14W-3FM-210) - Cub Cadet Tractor (2013) - Front Axle Assembly
Cub Cadet GTX2100 (14W-3GE-010, 14Y-3GE-010) - Cub Cadet Garden Tractor (2011) - Front Axle Assembly 1 inch axle
Cub Cadet GTX2100 (14W-3GE-010) - Cub Cadet Tractor (2013) - Front Axle Assembly
Cub Cadet GTX2154LE (14W-3GEC010) - Cub Cadet Garden Tractor (2011) - Front Axle Assembly 1 inch axle
Cub Cadet XT2-GX54 (14AHA3CA010, 14WHA3CA010) - Cub Cadet XT2 Enduro Series Lawn Tractor, Fabricated Deck (2015) - Front Axle
Cub Cadet XT2-LX42 (13AGA1CS010, 13WGA1CS010)- Cub Cadet XT2 Enduro Series Lawn Tractor (2015) - Front Axle
Cub Cadet XT2-LX46 (13AFA1CT010, 13WFA1CT010)- Cub Cadet XT2 Enduro Series Lawn Tractor (2015) - Front Axle
Cub Cadet XT2-LX50 (13AIA1CQ010, 13WIA1CQ010)- Cub Cadet XT2 Enduro Series Lawn Tractor (2015) - Front & Rear Wheels
Cub Cadet XT2-LX54 (13AIA4CA010, 13WIA4CA010) - Cub Cadet XT2 Enduro Series Lawn Tractor, Fabricated Deck (2015) - Front & Rear Wheels
Cub Cadet XT2-LX54 (13AIA1CW010) - Cub Cadet XT2 Enduro Series Lawn Tractor (2015) - Front & Rear Wheels
Cub Cadet Z-Force S 48 (17AI5BHB, 17AI5BHB010, 17AI5BHB009, 17AI5BHB056) - Cub Cadet Residential Z-Force S 48" Zero-Turn Mower, 22 HP (201 - Steering Column & Axles
Cub Cadet Z-Force S 48 (17AI5BHB, 17AI5BHB010) - Cub Cadet Residential Z-Force S 48" Zero-Turn Mower, 21.5 HP (2013) - Steering Column & Axles
Cub Cadet Z-Force S 48 LP (17AP5BHB710) - Cub Cadet Zero-Turn Mower, 726cc Kawasaki - Steering Column & Axles
Cub Cadet Z-Force S 60 (17AI5GHD, 17AI5GHD010, 17AI5GHD210) - Cub Cadet Residential Z-Force S 60" Zero-Turn Mower, 26 HP Kawasaki (2010) - Steering Column & Axles
Cub Cadet Z-Force S 60 (17AI5GHD, 17AI5GHD010) - Cub Cadet Residential Z-Force S 60" Zero-Turn Mower, 24 HP Kawasaki (2013) - Steering Column & Axles
Cub Cadet Z-Force S 60 LP (17AP5GHD710) - Cub Cadet Zero-Turn Mower, Kawasaki - Steering Column & Axles
Cub Cadet XT-2 LX46 FAB (13WQA4CN010) - Cub Cadet XT2 Enduro Lawn Tractor (2016) - Hub Caps
Cub Cadet XT2 LX46 LE FAB (13AGA1CN010) - Cub Cadet XT2 Enduro Lawn Tractor (2016) - Hub Cap
Cub Cadet XT2-LX42 KH (13BPA1CS010) - Cub Cadet XT2 Enduro Lawn Tractor (2016) - Hubcap
Cub Cadet XT2-LX42 KH (13WPA1CS210) - Cub Cadet XT2 Enduro Lawn Tractor, Carb (2015) - Front Axle
Cub Cadet XT2-LX42 KH (13WPA1CS010, 13APA1CS010) - Cub Cadet XT2 Enduro Lawn Tractor (2015) - Front Axle
Cub Cadet XT2-LX42 KW (13WGA1CS210) - Cub Cadet XT2 Enduro Lawn Tractor, Carb (2015) - Front Axle
Cub Cadet XT2-LX46 FAB (13WIA4CN210) - Cub Cadet XT2 Enduro Lawn Tractor, FAB, Carb (2015) - Front Axle
Cub Cadet XT2-LX46 KH (13YQA1CT010) - Cub Cadet XT2 Enduro Lawn Tractor (2016) - Hubcap
Cub Cadet XT2-LX46 KH (13WQA1CT210) - Cub Cadet XT2 Enduro Lawn Tractor, Carb (2015) - Front Axle