I upgraded the bass and tom tom heads on my Pearl Rhythm Traveler kit (ASIN: B0002FO4R8) to these heads with amazing results. Before upgrading the open bottom toms had a lot of ring and were impossible to get the tone I wanted no matter how carefully I tuned them. I replaced the heads with these and was rewarded with an amazing difference in sound quality. The ringing, hollow quality I previously struggled to correct is now a nice "thump" sound that works perfectly with jazz and rock.