I tried using the one that's open, but the other one is a spare, so it's not open. Sold as a set of two. No individual sales. Compatible with iPhone. Charging is possible. Instruction manual is included, but it's in a language I can't read (foreign made). Immediate purchase OK. Significantly reduced from the purchase price. The purchase price was 500 yen each, 1000 yen for two in a bargain. I thought it would be just right to put them in a bag. There are 4 items in total. Price reduction is not possible.