The KESTER part 04-9574-0050 is an Ultrapure® K100LD Lead-Free Solder Bar, weighing 1-2/3 lbs. This solder bar is the ideal solution for various soldering applications that require a high-quality, lead-free solder. With its exceptional purity and precision formulation, K100LD offers excellent thermal and mechanical reliability, ensuring reliable and durable solder joints. Suitable for both manual and automated soldering, this solder bar is a must-have for professionals seeking top-notch performance and exceptional results.