These two very special super imposed ignitors are solely for use with a SON 100W but in conjunction with ballast for HPMV 125W (left one) or 250W (right one). This combination gives the possibility to use standard (long life and high output) HPS lamps on existing MV gear just by connecting this aparatus between the lamp and choke.
I ordered them in the very early 2000s as an option for street lighting refurbishment in the company I worked for at this time but sadly the costumer finally opted for entire new street light fixtures so we skipped the idea. These two are the only one I kept. In the past I had other wattages as well but I gave them away.