This is for an amber turn signal bulb for a scooter. R5W with two prongs 180 degrees from each other. I bought some RY10W bulbs thinking they were the replacement but the bulb that came out was a R5W 18321. The little pegs on the RY10W bulb is off centered, so they don’t fit into the bulb holder. The bulbs have to go through the hole into the housing, so the bulb head can’t be larger than the original one. Factory bulb on the left.