1VP68.7/8 Gates 1 groove variable pitch light duty sheave 6.55 (in) outside diameter, 7/8 (in) bore. Use with 3L, 4L, or 5L v-belts. Gates Product Number 7810-1844. Gates variable pitch sheaves are engineered for mechanical drive speed variations that are efficient, easy to install, and easy to adjust for your light-duty applications.