Callaway Big Bertha Heavenwood Hybrid. The design of the Callaway Big Bertha Heavenwood Hybrid clubs gives you all the performance of a long iron, combined with the forgiveness of a fairway wood. This results in fantastic playability anywhere on the course. The maximum amount of weight has been pushed to the heel and toe of the club to create increased stability and more resistance to club head twisting on off-centre hits, while the low profile design of the head gives a very low centre of gravity to make getting the ball in the air very easy. Callaway's VFT (Variable Face Thickness) Technology increases the distance off shots, even on off-centre hits. The sole of the Callaway Big Bertha Heavenwood Hybrid was made famous on the Warbird woods and this design has been modified to give a solid contact from virtually any lie.