Optical BK7 Windows are flat plane-parallel plates, which are often used to protect electronic sensors or detectors without blocking optical transmission. Optical Windows do not change the magnification of a system.

BK7 window is the most common type of window. It has good performance over visible and near infrared wavelength region.

BK7 window is ideal for applications require minimal transmitted beam deviation.

Material	N-BK7 grade A optical glass
Wavelength	350-2000nm(Uncoated)
Diameter Tolerance	+0.0, -0.1mm
Thickness Tolerance	± 0.2mm
Clear Aperture	>85%
Parallelism	<3"
Surface Quality	20-10; 10-5 scratch and dig
Flatness	λ/10 per 25mm @632.8nm
Wavefront Distortion	λ/10 per 25mm @632.8nm
Bevel	0.25mm x 45°