Scale Aircraft Conversions, or SAC, make replacement landing gear for a wide variety of aircraft, in all the major scales. They are cast in white metal, which is stronger than the kit’s plastic pieces. To quote the company’s website, “Some sets consist of the main gear only while others include the nose gear, tail gear and/or adjacent related components. Some inaccuracies in the original kit gear have been corrected but the mounting points remain identical to the factory parts.”
This set is made to replace the kit parts from the new tool Revell Halifax. It’s a large aircraft and will be a bit heavy when finished. Having the metal landing gear underneath will help support that weight. Additionally, they’ve changed the way the tail wheel and gear is assembled, making it simpler and making one less glue seam to remove.