Jolly Logic AltimeterTwo

For the compactness and features this Altimeter Two has is awesome! Plus it provides a lot of other information such as max thrust, avg thrust, coast time, time of ejection after apogee, descent speed, max speed, and total duration. I love it for redundancy if using a dual deploy onboard computer as it displays numbers and one does not have to count beeps. The USB port is only for charging and not for transferring data. Nonetheless, it is a great addition to make rocketry that much more entertaining and scientifically useful. The button seems challenging to press but once one reads the instructions it is clear just press it like you would normally and it will activate. The display needs to be read at the proper angle as it is not that bright. But it keeps the information as long as it has power so you can read it in better lighting conditions. I was able to use it on two other launches and it worked great even when the nose cone came off but the parachute was stuck inside the rocket. It said the rocket descent speed was 57mph! Alas, it was a 6' long Estes Mean Machine so it is now about a 5'6" Mean Machine and the Altimeter two that was wrapped in 1/2" pipe insulation and a rubber band suspended from the nosecone works great! The only issue I had is I could not get it to charge. After reviewing their website support page I found on tip was to use a USB extension cable and after trying it in 6 different USB ports on two computers I was ready to give up. I even had it fail on a trip to ROCstock due to battery drain. Nonetheless, I the cable works and I now have it fully charged and ready to go next time.

Much more reliable and accurate than the Estes version, plus a massive amount of data comparatively. Yes, it's more expensive than the "toy" option, but it's worth it if you really want to collect data about your launches. The Estes one is fine if you just want a fun toy to see how high your low-power kits got, but be warned that it doesn't seem to be as accurate overall. One other thing that the instructions cover, but I want to remind you. If you don't vent your rocket with at least two small holes, the pressure inside the model won't match the outside pressure, and you will not get accurate readings. I know some people might not like making holes in their perfect paint jobs, but if you want any altimeter to be accurate, you need to do this. Just find two unobtrusive places and drill small 1/8th inch holes in the body tube.

We purchased the Altimeter Two so that my son could do his science project with homemade rockets. I didn't think we needed this altimeter because it offers a lot of data - more than I thought would be useful. Even though we could have lived with the simpler version, this altimeter is awesome! It records so much and really puts the life of the rocket launch in to workable data. Overall, it is really simple to use and very hardy. We did create a little "booty" for it. We cut up an old sock, stapled it and slipped the altimeter in to give it some extra protection. We had a few failed missions where the parachute didn't open and the altimeter worked well and didn't appear to have a scratch on it. Just be sure to charge it before launch and turn it on before you go. You won't be disappointed.

very good: fast shipment , good work

Tells you apogee, delay time, Mach speed, time of flight, etc....these really are incredible items to have for model Rocketry...rsbhunter

At first, I was disappointed since I thought that this would download data to my PC (it is charged via usb). However, after using it I realized that I don't really want the complication of having to download data after every launch (who wants to bring their computer to every launch?). It records all the parameters needed to calculate different weight/thrust combinations and to hit a target altitude for TARC. I'm not into high power yet, but it works up to 9,999 meters so it should work fine for that too. Works great, it's light weight (8g) and has survived many landings where it hit usb contact side first on pavement without any damage. Highly recommended.

Small in size, Large on features!!!! This altimiter gives you 99% of the data you need to know how your engines perform. Tells altitude, time of flight, speed, etc. Easy-to-use, rechargeable, And small enough to use in most rockets!!!!

Broke quickly into using it. Do not purchase.