StratoFins Screw-on Water Rocket Fins - Compatible with 2 Liter Bottles or Smaller

My 2-3 year old son and I have been launching bottle rockets in our yard and in fields around town for the past two summers. After about 200-300 launches, we finally managed to destroy the the foam fins that came with the Quest Aerospace Deluxe Single Water Rocket Set.My wife just got me these StratoFins for father's day, and my son and I love them. They make refilling the rocket much easier compared to the foam fins that we'd been using. These are easier to unscrew and re-screw on while refilling the bottles. Also it's easier to switch between bottles because the same fins can be used on multiple bottles, no need to make new fins for every bottle.We've used our StratoFins for a few dozen launches each on both 1liter and 2 liter bottles, and they work great. I think they'll last many more flights than the foam ones (which I was about to replace with self made replacements before I was surprised with these as a gift. We've had maybe five launches that landed on asphalt or in the gravel on tI hhe edge of the road. There is not a single sign of damage or even any marks that didn't easily wipe off with a shirt tail.The Stratofins came with a flat black rubber gasket inside the female end of the connector, and it creates at least a good a seal between bottle and Stratofins as the seal between the Stratofins and the Quest Aerospace nozzle that we're using.It's fun to use and decorate foam, cardboard or wooden fins when you first get into bottle rocketry. If you're wanting to conduct a range of experimental flights with different rockets or other changes of setup of other elements (other than the fins themselves) these are great. They are perfectly compatible with the Quest Aerospace launcher, and I haven't seen another launcher (store bought or homemade that they wouldn't work with, because they just replicate the bottle's threads on the aft side of the fins. The red color also makes for ideal visibility regardless of whether the sky is blue or overcast.

A little pricey for what they are, they do work great, and are a useful backup if the identical fins in their launcher kit get lost or broken.Of course, you can launch bottles with (or without) these, from about any launching stand, not just Relationshipware's, but they do stabilize the bottle in flight, and also make those bottles look like a "real" rocket.After experiencing a few launches, I'd say the likelihood of breakage is pretty small, and a single broken fin can be replaced 3 times from a spare set, as they are separately fitted. Most likely problem: loss on a windy day. Unless you have a huge open area to launch in, the bottles can go so high that the wind will carry them hundreds of yards, onto fenced properties, roofs, wood lots, weed patches, ponds, lakes or rivers, etc. Launching near Area 51? If the wind is blowing that way, keep the air pressure low!The Relationshipware launcher (with the "extra hole" modification) works so well that a spare set of fins is worth it to insure that increased altitude and "real rocket" looks aren't cut short by a mishap.

Really added altitude and and a strait flight. Broke after a handful of uses when a small part around where the fin slides in snapped.

Easy to use and sturdy fins for water bottle rockets. This is a good company that makes it easy to get flying. Of course, the only downside is the costs. But if you're in a hurry or don't feel like making it all, this is one of the best with guaranteed results.

Holds up great after many uses, definitely works well to keep a bottle rocket on a straight and vertical launch. I would say this kit does add to the overall experience and it’s absolutely worth the extra few dollars to help keep the rocket from landing on the roof.

These fins pair great with the strato launcher.

The internal diameter is just a little bit bigger than that of a 2 liter bottle. I used it with an Aquapod launcher and the fit is not right leaking air. The bottle on its own fits perfectly and flies very high but with these fins attached the air starts to leak after the second pump. It is a shame as one of the product pictures shows it with an Aquapod launcher.Update December 29:As per manufacturer's suggestion I will try later with a thicker O-ring. In the meantime I used a strip of plastic from a supermarket bag. I folded it over once and rolled 5 times around the connection pipe (for a total of 10 layers of plastic). This made the fins to work and the difference i simply astounding.I had the idea that the fins only got a straighter flight but the range is also affected. Now the height is about twice of what I could get before. With this quick fix I can tell you that these fins are a must

Here's the good and the bad.... the product is good however in the directions it tells you if there is a leak to go to the hardware store and buy a O ring...it gives the exact number and stats its supposed to be... I have the Aeropod launcher which is the one they show in the picture... my thought is they knew before they sent this to me that it would not fit the 2 liter bottle perfectly and tell everyone to go to the store etc... well thats not cool... especially since my kid was super disappointed.... besides i shouldnt have to go to the store to fix their product.... anyway thats my two cents...