Callaway big bertha os ladies hybridwomens big bertha os hybrids are designed for super charged distance and ultimate forgiveness with a deeper body larger and faster face and next generation face cup technologyexplosive distance from next generation hyper speed face cupnext generation hyper speed face cup promotes faster ball speed across the face especially on off center hitslarger and faster face for more ball speeda larger and more flexible face helps in two ways 1 the added size gi