Carbine buffer tubes
the top 2 are mil-spec diameter . I don't remember the make the middle one has a lip that extends out and captures the buffer detent and the rear of the carrier rest on in might make a good poor mans version of the PWS piston buffer tube.
Both of the milspec tubes are $30 each.
the 3rd one is a commercial stock it is $25
I have another buffer tube Identical to the 3rd one I believe its for a Armalite AR10 as it almost 3/4" deeper than all my other buffer tubes. its in VG condition $30
The upper 2 are G-shock stocks. One has a broken lever and the other has some damage from someone mounting a shell holder on it and part of the lever was filed both are fully usable but I suggest you inspect before you buy they are great stocks if using a .308 or even a 6.8spc or grendel but they have a built in shock absorber $40 each.
The one below it is sig ar15 carbine stock The buffer tube is not original to it. I mate stocks with snug buffer tube because I hate a loose wobble fit. then one has a nice swoosh when you open it stock with buffer tube $60
I have 3 colt clone fiberlite stocks these fit mil-spec length Commercial diameter buffer tubes the middle one although hard to tell is factory not painted OD green these are $40 each
This one is a palmetto stock that fits a mil-spec diameter tube. I am trowing the extra as a freebie as i am sick of it being in my parts box the lever on it is screwed up might be good for parts . $15