NuTone LA301WH Decorative Flowing Design Wired Two-Note Door Chime, White Two-note chime for front door and one-note chime for second door Uses 16-Volt transformer model C905 or new C915, sold separately Can easily replace existing two-note chime without rewiring Chime Dimensions: 8-Inch Width x 9-Inch Height Flowing design and white finish offer understated class