Here is a custom made Flexi-Coil air Cart Coarse Meter roller with a Custom Helical Twist. Meant to be the same as a #7245 but with a helical twist. 

This should fit models 1330, 1720, 1740, 2320, 2340, 2640, 2850, 3174, 3234, 3350, 3450, 3850, 4350.  This also fits certain Case and JD models with the same style meter roller.

The meter roller dimension is approx 3 1/8 tall with an approximate diameter of just over 3 1/4 inches.  Hex shaft is approximately 1 1/8 between the flats.

This is said to provide more even seed distribution as the seed will slowly roll off rather than all at once.Many have sold with no failures reported.

 Can make for other makes and models.

See my other listings for the other rollers and air seeder parts.