This is a rare Summicron 5cm f2 in LTM screw mount with thorium glass. The Thorium lenses have a tendency to have a yellow tint to the glass, this one has a cool noticeable yellowing to the glass.
The glass is average for these. There are a series of fine marks on the front and rear elements that may soften your images slightly. There is no haze or fungus but there is a slight yellowing caused by the thorium. The focus and aperture are smooth.