The kit consists of twelve pieces of a particular type and grade of rubber-like synthetic polymer, specifically selected for its damping properties at the frequencies which cause problems within LP replay systems. We were so impressed with the results of our initial experiments that we had a tool made to accurately cut the material into triangle shapes which press fit perfectly into the recesses in the sub-platter. Fitting is a five minute job - simply remove the main platter and firmly push them into place. The results are quite audible and easily justify the cost. You can, of course, fit an additional set to the underside of the sub-platter for even more sonic improvement but you will need to glue this set in place using superglue. If you order two sets you only pay shipping on one set. The second picture shows a sub-platter with the kit fitted. Please note the sub-platter itself is not included.