these r good for cell phones and tablets- any device with a standard headphone jack_ also works without plugging it into a headphone jack- so u could use as a stand alone flash light.did not buy mine here_but i'm glad i got them- bought 2 of them. they're rechargeable- came with the usb/micro-usb charging cable.with the rechargeable battery u won't have to worry about the light using up your phone/tablet batteryi was surprised that these 1 1/2 inch square lights came with so many features: rechargeable, on/off, low/med/hi, cable 2 charge with.there's a small hole between the mini usb charging port and the metal plug- u can string a hanging cord or thread to hang/hook the light on the phone case or wherever u want.**the mini flash that have a metal post/plug will make your phone think that headphones are plugged into the phone- so the phone won't ring and sound won't play if u try to play music/vids...(that's what happens with my Samsung Galaxy S4) if u buy the kind with a plastic post u won't have 2 worry about that_ but they may not be a durable as the ones with the metal post.they're small enuf to carry in pocket, coin purse_ or toss in glove box, drawer, in your loose change bowl, etc- they're just a little bit bigger than a quarter - i'll include some pics and lay a quarter on top of it- so u can see.when they're charging a dim red light in the corner will light up- when the light goes out, it's fully charged- doesn't take long.this listing is currently selling for $4.-ish_ if u can get these for $5 or less- it's a good value_ get 1 for every phone and get a few for friends. i'll include pics with my review-_Amazon has these lights for as little as $3- so look around b4 buying.i hope some of the info i shared was helpful_ thank U