Sage Electrochromics. The company now offers its electronically tintable glass, which uses nanotechnology to allow occupants to control daylight and solar heat transmittance, in combination with triple-pane construction for R-values greater than 8. The tintable glass can be controlled between completely clear, with an SHGC of 0.48, up to heavily tinted (during times of direct sunlight) for a 2% visible light transmittance and an SHGC of 0.09. The glass can be zoned into different tints, thereby allowing for direct sun to be blocked while maintaining a clear lower zone to transmit ambient light. 507.331.4848. http://sage-ec.com.