You're bidding on a 1951 Franklin silver half dollar graded MS64 with full bell lines.  The new ANACS holders are highly desirable because the garde and type of coin can be seen without taking it out of a box.  Also, ANACS has tightened up thieir grading standards considerably.  YouTube abounds with videos re ANACS grading.  They're considered tops along with NGC and PCGS  whose standards are an enigma to almost anyone you discuss this topic with.