This is a Cub Cadet Spring Extension 732-0384. It fits 

Cub Cadet LTX1040 (13AX90AS010, 13RX90AS056, 13AX90AS009, 13WX90AS010, 13WX90AS009) - Cub Cadet Lawn Tractor (2010) - Mower Deck 42-inch
Cub Cadet LTX1040 (13WX90AS010, 13WX90AS056, 13WX90AS009, 13WX90AS256, 13WX90AS210) - Cub Cadet Lawn Tractor (2011) - Mower Deck 42-inch
Cub Cadet LTX1040 (13WX90AS010, 13WX90AS056, 13WX90AS009, 13AX90AS210, 13WX90AS210) - Cub Cadet Lawn Tractor (2012) - Mower Deck 42-inch
Cub Cadet LTX1040 (13WX90AS010, 13WX90AS009, 13WX90AS056, 13WX90AS256, 13AX90AS256) - Cub Cadet Tractor (2013) - Mower Deck 42-Inch
Cub Cadet LTX1040 (13AX90AS056, 13WX90AS009, 13WX90AS010, 13WX90AS056, 13WX90AS256, 13AX90AS010, 13AX90AS256) - Cub Cadet Lawn Tractor (20 - Mower Deck
Cub Cadet LTX1042 (13AX91AS010, 13WX91AS010) - Cub Cadet Lawn Tractor (2010) - Mower Deck 42-Inch
Cub Cadet LTX1042 (13YX91AS010, 13YX91AS210, 13BX91AS010) - Cub Cadet Lawn Tractor (2011) - Mower Deck 42-Inch
Cub Cadet LTX1042KH (13AP91AS010, 13AP91AS056) - Cub Cadet Tractor, 22 HP Kohler (2013) - Mower Deck 42-Inch
Cub Cadet LTX1042KW (13WG91AS010, 13WG93AS010, 13AG93AS210, 13WG93AS210, 13AG93AS010) - Cub Cadet Lawn Tractor (2012) - Mower Deck 42-inch
Cub Cadet LTX1042KW (13WG93AS010) - Cub Cadet Tractor, 18 HP Kawasaki (2013) - Mower Deck
Cub Cadet LTX1042KW (13WG93AS010, 13WG93AS210, 13AG93AS010, 13AG93AS210) - Cub Cadet Lawn Tractor (2014) - Mower Deck 42-Inch
Cub Cadet LTX1045 (13AX91AT010, 13RX91AR056, 13WX91AT010) - Cub Cadet Lawn Tractor (2010) - Mower Deck 46-Inch
Cub Cadet LTX1045 (13WX91AT056, 13WX91AT010) - Cub Cadet Lawn Tractor (2011) - Mower Deck 46-Inch
Cub Cadet LTX1045 (13WX91AT056, 13WX91AT010, 13AX91AT010, 13AX91AT056) - Cub Cadet Lawn Tractor (2012) - Mower Deck 46-inch
Cub Cadet LTX1045 (13AX91AT056, 13WX91AT010, 13WX91AT056) - Cub Cadet Tractor, 20 HP Kohler (2013) - Mower Deck
Cub Cadet LTX1045 (13AX93AT056, 13WX93AT009, 13WX93AT010, 13WX93AT056, 13WX93AT210) - Cub Cadet Lawn Tractor (2014) - Mower Deck 46-Inch
Cub Cadet LTX1046M (13WP91AT010, 13WP91AT009, 13WP91AT210, 13AP91AT010) - Cub Cadet Lawn Tractor (2011) - Mower Deck 46-Inch
Cub Cadet LTX1046M (13WP91AT010, 13WP91AT009, 13WP91AT210, 13AP91AT010) - Cub Cadet Lawn Tractor (2012) - Mower Deck 46-inch
Cub Cadet LTX1046M (13WP91AT010, 13WP91AT009, 13WP91AT210) - Cub Cadet Tractor (2013) - Mower Deck 46-Inch
Cub Cadet LTX1046M (13WP91AT010, 13WP91AT009, 13WP91AT210, 13AP91AT010) - Cub Cadet Lawn Tractor (2014) - Mower Deck 46-Inch.