[. . . ] Microwave Hood Combination PRODUCT MODEL NUMBER WMH31017A Electrical: A 120-Volt, 60-Hz, AC-only, 15- or 20-amp electrical supply with a fuse or circuit breaker. [. . . ] Exact dimensions may vary depending on type of range/cooktop below. Page 1 of 2 Because Whirlpool Corporation policy includes a continuous commitment to improve our products, we reserve the right to change materials and specifications without notice. For complete details, see Installation Instructions packed with product. W10609724A 11/12/13 A 3¹⁄₄" x 10" (8. 3 x 25. 4 cm) rectangular or 6" (15. 2 cm) round vent should be used. The total length of the vent system including straight vent, elbow(s), transitions and wall or roof caps must not exceed the equivalent of 140 ft (42. 7 m) for either type of vent. To calculate the length of the system you need, add the equivalent length for each vent piece used in the system. See the following examples: Recommended Standard Fittings A B C Rectangular to Round Transition for Roof Venting NOTE: The minimum 3" (7. 6 cm) clearance must exist between the top of the microwave oven and the rectangular to round transition piece so that the damper can open freely and fully. A B C D E F G A. Rectangular to round transition piece: 3 " x 10" to 6" = 5 ft (8. 3 x 25. 4 cm to 15. 2 cm = 1. 5 m) B. 90° flat elbow: 3 " x 10" = 10 ft (8. 3 x 25. 4 cm = 3 m) D E 3" (7. 6 cm) F A. [. . . ] For complete details, see Installation Instructions packed with product. [. . . ]