This is a Cub Cadet 111 182 282 382 383 76 80 81 Seat Spring. This is a New Old Stock part. Part No. 703-0354  (2b)

All Models:

111 (0350025U) - Cub Cadet Lawn Tractor - Seat & Support
182 (134-182-399, 133-182-399, 0350030U, 132-182-399, 133-182-100, 132-182-100, 134-182-100) - Cub Cadet Lawn Tractor - Seat & Support
282 (133-282-399, 132-282-100, 134-282-100, 133-282-100, 132-282-399, 134-282-399, 0350026U) - Cub Cadet Lawn Tractor - Seat & Support
382 - Cub Cadet Lawn Tractor, Gear - Seat & Support
383 - Cub Cadet Lawn Tractor, Hydro - Seat & Support
76 (0350001U, 0350009, 0350010) - Cub Cadet Lawn Tractor - Seat & Support
80 (0350002U, 0350021U) - Cub Cadet Lawn Tractor - Seat & Support
81 (0350003U) - Cub Cadet Lawn Tractor - Seat & Support