I have purchased Led Lenser K1 and K1L from a local web store about 4$ each on sale.
They are fine little lights. Both use 4xAG3 batteries.
Both has same led and lumens. K1L has a ligth ring on the head side and a bit longer than K1.
Here are some pictures showing the products.
I’ve got a K1L on my keys, light and compact and enough light to find the keyhole without stripping paint off the door and lighting up the neighbourhood.
I know I paid way more than $4 for mine easily double that.
Edit…………Beware of the swivel on the supplied keyring it can and will separate, the split rings aren’t bad but I’d ditch the swivel, mine lasted about 3 months and parted as I put my keys on my bedside table - luckily.