Butterfly Jigs come in three different versions.  Regular, Long and Flat-side.  The Flat-side is the newest version.  Once you determine which version you will need then determine the weight of the jig.  Regular Butterfly jigs are available from 2 oz to 9.5 oz.  The Long Jig is available in 4.5 oz and 7oz. and the new Flat-side jigs are available in 4 oz. through 12 oz versions.