RINEHART 4.5″ HP45 XL SLIP-ON MUFFLERS. 4.5″ Slip-on mufflers. Designed to work with stock head pipes.. For riders that want a full length muffler, the HP45XL brings a fresh style and finish paired with race-inspired performance and power you’ve come to expect from Rinehart.. A perfect match to ST Touring and Anniversary models, the HP45XL brings industry-leading engineering and unmatched style to any HD Touring bike, and packs the iconic Rinehart Rumble that has set us apart for years.. 100% American made and backed with our Forever Warranty, guaranteeing the quality that Rinehart is known for the world over..