An in-betweener, the Inland Surfer Tweeners Wakesurf Fins are sized between the Big Boy and the Inline Standard fins. The Tweener fins give you a little more added thrust than the Standard yet not as much as the Big Boy fins, yet allows smoothness, rail to rail allowing great jumps, spins and down the line speed. These fins are built for the Inland Surfer "surf" style boards, NOT for use on any 4-Skim models.