Who makes this antenna?
Those look like generic antennas to me. Probably made at t he same factory as the MFJ, etc..models are and labeled differently. For $25 buy one a try it out. You're not going to find a lot of difference in any brand of VHF/UHF antennas as far a performance goes comparing apples to apples. There can be big differences in quality and build and how long the antenna will last before it falls apart.
as long as its a god performer like my tram 1150. wanted something shorter but with out sacrificing gain. could have went with a comet but it had unity on 2 and a small gain on 70cm
Don't worry too much about gain on 2m and 70cm. If you looking at hitting the local repeaters your not going to be able to tell a bit difference between unity and a few db of gain measured against isotropic or dipole for that matter. In the real world most of us are seeing full meter deflection and full quieting into local repeaters anyway.
Heck, I hit a local repeater 7 miles away with a micro ht and a 3" antenna!!!
Just find an antenna that is built well and covers both bands. Don't sweat the gain figures.