We present the optical spectra of four newly discovered gravitational lenses from the Cosmic Lens All-Sky Survey ( CLASS ) .
These observations were carried out using the Low Resolution Imaging Spectrograph on the W. M. Keck-I Telescope as part of a program to study galaxy-scale gravitational lenses .
From our spectra we found the redshift of the background source in CLASS B0128+437 ( z _ { s } = 3.1240 \pm 0.0042 ) and the lensing galaxy redshifts in CLASS B0445+123 ( z _ { l } = 0.5583 \pm 0.0003 ) and CLASS B0850+054 ( z _ { l } = 0.5883 \pm 0.0006 ) .
Intriguingly , we also discovered that CLASS B0631+519 may have two lensing galaxies ( z _ { l, 1 } = 0.0896 \pm 0.0001 , z _ { l, 2 } = 0.6196 \pm 0.0004 ) .
We also found a single unidentified emission line from the lensing galaxy in CLASS B0128+437 and the lensed source in CLASS B0850+054 .
We find the lensing galaxies in CLASS B0445+123 and CLASS B0631+519 ( l, 2 ) to be early-type galaxies with Einstein Radii of 2.8 - 3.0 ~ { } h ^ { -1 } kpc .
The deflector in CLASS B0850+054 is a late-type galaxy with an Einstein Radius of 1.6 ~ { } h ^ { -1 } kpc .