Awful. Just awful. Don't buy this utter rubbish. It's terribly designed - I opened it out of the packet, took the twist cap off to put the battery in, and the very thin flimsy bit of metal that is in the bottom of the cap, which is essential to make complete the circuit to turn it on - immediately twisted with the product. Irreparably.
I had the product a sum total of 15 seconds before it broke due to a defect with the design. It is literally not worth your trouble to get this product. Stay clear of it.