I think you make a mistake because there is not any bay15s bulb holder in the market.

Most of bulb holder shall be bay15d or ba15s.

Bay15d bulb holder is for daul filament bulbs.

And ba15s bulb holder is for single filament bulbs.

My factory can produce all kinds of top quality bay15d and ba15s bulb holders now.

Our bay15d and ba15s bulb holders are all using “Ceramic and high-temperature resistance” materials.

In order to make you clearly our best bay15s bulb holder, I will show you pictures as below.