The turnbuckle batten with hole allows the adjustment of the forestay and the shrouds in order to adjust their tension and the quest for the mast.
This turnbuckle batten is found on almost all catamarans in the Hobie range.

Stainless steel, sold without drilled axle and split ring

To adjust the height of the turnbuckle slat, you will need drilled axes 98220034.