These binoculars use Roof Prisms, they are 10 x 50 magnification, so they will make a good bird watching tool. They might even be good for gazing at the Moon. 

These binoculars measure approximately 7 1/8th inches long, 5 3/8 inches (Max width), 

2 3/8 inches top to bottom.

The ocular lenses are approximately 18 mm, the objective lenses are approximately 50 mm.

On the focus adjustment it reads "10 x 50" over '99m/1000m". Opposite the focus knob they are labeled "Made in Japan" There is also a stamp that reads "B35".

 On the hinge bridge it is labeled "ASUMAMA" over No.000156.

There looks to be a oval foil inspection sticker on one of the objective lens frames, but It is almost worn away. 

The lenses are coated and look to be free of any scratching, chips or fogging.

But when looking through the objective lens there looks to be a arched imperfection on the prism, but it is not visible when sighting through the ocular lens ?

ASANUMA is Japanese company better known for manufacturing camera lenses, but these vintage binoculars are pretty nice.