The DT is an FCS, skim style fin. The DT 1 is the Fireball boards stock center skim fin replacement, while the DT 1.5 offers increased skim style grip.
https://www.phase5boards.com/blogs/phase-5-wakesurfers-blog/phase-5-finology
5FINDT1
The DT is an FCS, skim style fin. The DT 1 is the Fireball boards stock center skim fin replacement, while the DT 1.5 offers increased skim style grip.
https://www.phase5boards.com/blogs/phase-5-wakesurfers-blog/phase-5-finology