PSL aka Romak3 is a 7.62x54R AK clone. It’s a Comblock designated marksman rifle popular in the US mainly because it is far more affordable than the Soviet SVD. It usually comes with either just iron sights or a truly wretched 6x scope on a high side rail mount.
Best examples of this gun yield 1-1.5MOA. In .30 caliber semi-precision rifles, PSL is a fairly economical pick that can be further improved with better optics and forend.
Which is precisely what TWS rail cover and forend provide. The 10x scope shown allows the cover to be unlatched for cleaning while keeping zero.