This spectrum tube holder allows an external power source to be used with 26cm long spectrum tubes. It is fitted with 4mm safety sockets on a black panel for secure electrical connections. The holder includes a bosshead attachment that allows it to be clamped onto any laboratory stand, providing flexible positioning for spectroscopy demonstrations. A stand is not included. This holder is designed for physics classrooms studying atomic emission spectra, where individual gas tubes are illuminated to observe their characteristic spectral lines.