Spirit Airlines Baggage Policy
The Spirit Airlines (NK) baggage policy for regular basic fares include the following:

Carry-on baggage - Subject to applicable fees.
1 personal item - Fee free
1 carry-on item - Subject to applicable fees
Checked / hold baggage - Applicable fees per bag increase with number checked beyond 2 bags
Overweight and Oversize bags - Applicable fees per bag depending on weight and size categories
Sports equipment - Certain items might have applicable fees
https://petbaggagepolicy.com/s....pirit-airlines-bagga