New Blank, Rare Spine!!!!!!

Hi Again, I Cn´t Believe This, Today I Recieve A Sage Xp 796 Blank And When I Was Lookin At It I Try Easy To Look For The Spine, And Now I Am Looking At It, It Has Two Spines!!!!!!!!, This May Be Sound Crazy, But Yes!!!!, It Has Two Softer Sides And Two Harder Sides. Do You Know Something Of This?????, Thank You, Marcelo.