If it is the same one I have, it is about 13 inches long, and has built in lens hood,
it is not internal focus, but rather the front element moves about 28 mm for focusing to minimum distance.
It also has integral tripod mount.
Biggest problem I have had is the 22 foot minimum focusing distance,
which is about double my SMC-P 300mm f/4.0
It is also slow enough that it cannot be used with the 1.7x AF TC, where as my 300 f/4 can.
For large wild life, it is not too bad, but for birds, while, I find I can sneak up closer than 22 feet usually.
I got mine new in 1982 for $169 cdn as an inventory clear out.