Title sums it up pretty good. Looking at keychain and ultralight weight red lights. Budget is a huge factor as it will only see very limited use. I also am strongly partial to primary batteries due to the low runtime it will see.
I’m aware of basically the following
Inova microlight
Photon Microlight 1/2/freedom
Nitecore Tube (rule out due to integral li-ion cell)
I see the Photon 1 and Freedom are rated for IPX-7 but I don’t believe the Inova or the Photon 2 have any true water resistence rating… Although I did carry a photon 2 for probably 5-8 years back in the day and never had a problem.
Is there another good option out there? Definitely want to keep it on a TIGHT budget but I don’t want to fool around with those fauxton lights unless somebody can vouch for a particular brand/model/vendor. Another option would be something in a 1xAAA format but I’m not aware of any lower cost, decent quality options in that size.
Not sure what your definition of “TIGHT budget” is… I just picked up a Manker E02 that’s red and you can get it with Nichia 219c, too. It’s around $23. Quality is good. Moonlight mode is programmable.
However, it does have a magnetic tail. To me, that’s a plus, but if you are truly planning to use it as a keychain light, then it might just be a hindrance.
Sofirn is developing a 1xAAA light with 5mm leds at the moment, the BLF version will be housing high CRI Yuji leds but likely they will make a red led version too.
But it can be half a year before it is there