My S-I-L has some generic brand of one of the little tiny chain saws that is probably best described as one handed pruning saw. The thing works great. I've used it several times, it has some funky battery, not compatible with anything but the little saw works very well. Her's has an oil reservoir for 'bar & chain' oil. Its light. But it has managed to cut everything I've tried to cut with it.
For father's day my wife, knowing that I had been using her sister's little saw, bought me the RYOBI version of the mini chain saw.
The RYOBI variant is designed differently, it is much heaver but not a burden. First thing I noticed is you don't use bar & chain oil with this saw! Not sure how they do that. Ryobi uses a tool-less bar/chain adjustment knob, which is handy when you knock the chain off. I've done that twice in 3 days, but both times I'll admit that I was really pushing the little saw's abilities. And those abilities are considerably more than you might guess.
I've now used it for 3 days straight pruning back the paths through our trees. I put a 6amp/hour battery on the saw the first day. Big mistake. The saw is apparently very efficient, and I ran out of energy LONG before the battery was ready to give up. Yesterday I put a 3amp/hour battery on the saw and the battery and my stamina gave out right about the same time. Today I used a 4amp/hour battery and ran the little saw for well over an hour before knocking the chain off and deciding that was a good time to stop cutting.

I've been cutting some pine, some sumac, lots and lots of very hard hawthorn, some locust and a lot of unidentified scrub.
My main tractor path is about 100 yards long coming down a hill, it was about 15'-18' wide and over the past several years has seen mother nature narrow that to 10'-12' wide. So only using this little saw, I've reclaimed the full with. We have a grove of hawthorns and pines that I have now uncut to 8' so I can get under the branches with the tractor. Similarly a few other paths were widened and the low branches were cut up to allow the 8' roll cage to fit under the branches.

My observation is that YOU SHOULD GO TO THE STORE ANY BUY ONE.
I'm not advocating any brand.
Whatever brand your tool battery, buy that version.
But if you have woods and do lots of annual trimming, these things are awesome. Much easier than a little limbing saw. Much easier than an electric chain saw. Minimal vibration. Maximum convenience.
For father's day my wife, knowing that I had been using her sister's little saw, bought me the RYOBI version of the mini chain saw.
The RYOBI variant is designed differently, it is much heaver but not a burden. First thing I noticed is you don't use bar & chain oil with this saw! Not sure how they do that. Ryobi uses a tool-less bar/chain adjustment knob, which is handy when you knock the chain off. I've done that twice in 3 days, but both times I'll admit that I was really pushing the little saw's abilities. And those abilities are considerably more than you might guess.
I've now used it for 3 days straight pruning back the paths through our trees. I put a 6amp/hour battery on the saw the first day. Big mistake. The saw is apparently very efficient, and I ran out of energy LONG before the battery was ready to give up. Yesterday I put a 3amp/hour battery on the saw and the battery and my stamina gave out right about the same time. Today I used a 4amp/hour battery and ran the little saw for well over an hour before knocking the chain off and deciding that was a good time to stop cutting.

I've been cutting some pine, some sumac, lots and lots of very hard hawthorn, some locust and a lot of unidentified scrub.
My main tractor path is about 100 yards long coming down a hill, it was about 15'-18' wide and over the past several years has seen mother nature narrow that to 10'-12' wide. So only using this little saw, I've reclaimed the full with. We have a grove of hawthorns and pines that I have now uncut to 8' so I can get under the branches with the tractor. Similarly a few other paths were widened and the low branches were cut up to allow the 8' roll cage to fit under the branches.

My observation is that YOU SHOULD GO TO THE STORE ANY BUY ONE.
I'm not advocating any brand.
Whatever brand your tool battery, buy that version.
But if you have woods and do lots of annual trimming, these things are awesome. Much easier than a little limbing saw. Much easier than an electric chain saw. Minimal vibration. Maximum convenience.