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:
40mm (40 mm) High Temp Gray Silicone Dust Boot, Part Number 750.99005, Quantity 2
40mm (40 mm) Pressure Seal, Part Number 753.99005, Quantity 2
44mm (44 mm) High Temp Gray Silicone Dust Boot, Part Number 750.99007, Quantity 2
44mm (44 mm) Pressure Seal, Part Number 753.99007, 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:
143.99040K - 40mm
143.99044K - 44mm
This seal kit replaces OE Brembo Dust Boot part numbers:
20.4872.46 (20 4872 46) - 40mm
20.4872.48 (20 4872 48) - 44mm
This seal kit replaces OE Brembo Pressure Seal part numbers:
05.5955.58 (05 5955 58) - 40mm
05.5955.60 (05 5955 60) - 44mm
This seal kit replaces OE Brembo Rebuild Kit part numbers:
105.5955.58 (105 5955 58) - 40mm
105.5955.60 (105 5955 60) - 44mm
 
Typically on a 4-Piston caliper, there are two of each piston size, so this combination should service one front caliper (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.