Diamond A144S5 Base Station Yagi Beam

Easy to set up and works great, 50mi contact with an old radio right away. Why in the world was this thing set up for horizontal operation? I used an old shelf bracket I had to set it vertical.

Great antenna for the price

I purchased this antenna to experiment with and I am so happy I did. It's super easy to set up, I had to drill holes to set it vertical on the boom but no problem, centered the weight easily. I bought this to be able to simplex farther away (75 miles) with some friends and it's performance has been awesome. I have had an unexpected benefit with this antenna, although 2M only, I am able to transmit on the local 70cm repeater with low swr/1.2 and I'm super happy about that. I have it 25' in the air and use a tv rotator with no problems. Overall for the cost and 70cm benefit it's been a great purchase. 73

This is a great antenna from the perspective of construction, ease of assembly. It fails in that it is advertised with a photo showing vertical operation, but the package at the listed price does NOT include the side-arm. The antenna is a good deal for a horizontal antenna but with the added cost of the side-arm, this is a bad deal for a vertical antenna. It doesn't provide any system for vertical mounting without the side-arm. You can make your own of course, but you could buy the HyGain instead as well.
The assembly of the antenna is trivial. Just loosen the hand tightened wing nuts, rotate the elements to 90 degrees from the boom, and tighten the wing nuts. The antenna can't be tuned and doesn't need to be for 2m operation.
Beware of the mast mount requirements. It doesn't fit on a big mast. It works ok on a TV mast.
I haven't done objective performance testing, or comparison of the antenna against other horizontal antennas, but I have used it against a 5dBi omni and it is definitely better than the omni. My application was for fixed point to point links so the pattern of the antenna wasn't one of my considerations. YMMV?