The IS® 3100Z series includes a variety of premium performance, comfort, and convenience features that add even greater customer value to an already best-selling design. This mower offers supreme quality and reliability, plus an extraordinary package of components and benefits. The IS® 3100Z features the innovative iCD™ Cutting System. One lap on this machine and you will know… Ferris has done it again. Model Engine Deck IS3100ZB3061 30 gross hp B&S Commercial Turf Series* 61" IS3100ZBV3261 32 gross hp Vanguard BIG BLOCK* 61" IS3100ZBV3661 36 gross hp Vanguard BIG BLOCK* 61" IS3100ZBV32 W/3100/72 32 gross hp Vanguard BIG BLOCK* 72" IS3100ZBV36 W/3100/72 36 gross hp Vanguard BIG BLOCK* 7