These sets consist of high temperature heat resistant, silicone gray dust boots and high temperature pressure seals, designed for StopTech and most late-model Brembo calipers. These are the perfect components for street and track-oriented performance vehicles!
 
These are true, authentic, StopTech replacement dust boots and pressure seals and are recommended for track/racing/high performance driving events.
 
Included are the following components:
38mm (38 mm) High Temp Gray Silicone Dust Boot, Part Number 750.99004, Quantity 2
38mm (38 mm) Pressure Seal, Part Number 753.99004, Quantity 2
42mm (42 mm) High Temp Gray Silicone Dust Boot, Part Number 750.99006, Quantity 2
42mm (42 mm) Pressure Seal, Part Number 753.99006, Quantity 2
7.5 mL StopTech Pressure Seal Lubricant in squeezable dropper bottle (do not use on dust boots!) - This is absolutely the best lubricant to use when assembling rebuilt or new calipers.  Don't use brake fluid, use the proper lubricant instead - included free!
 
This is also StopTech Rebuild Kit part number:
143.99038K - 38mm
143.99042K - 42mm
This seal kit replaces OE Brembo Dust Boot part numbers:
20.4872.45 (20 4872 45) - 38mm
20.4872.47 (20 4872 47) - 42mm
This seal kit replaces OE Brembo Pressure Seal part numbers:
05.5955.57 (05 5955 57) - 38mm
05.5955.59 (05 5955 59) - 42mm
This seal kit replaces OE Brembo Rebuild Kit part numbers:
105.5955.57 (105 5955 57) - 38mm
105.5955.59 (105 5955 59) - 42mm
 
Typically on a 4-Piston caliper, there are two of each piston size, so this combination should service one front (4 pistons total).  These are not application specific, rather for those who may have a single torn dust boot or failed pressure seal or for those who are rebuilding their calipers; however, this kit will may work for many aftermarket Brembo or StopTech 4-piston caliper combinations.