The Cometic C10191-HB is a Multi-Layer Steel (MLS) cylinder head and base gasket kit designed for select liquid-cooled Harley-Davidson Milwaukee-Eight (M8) engines.

Key Specifications
Part Number: C10191-HB

Application: Liquid-cooled Harley-Davidson Milwaukee-Eight (M8) heads (fits 2017 Harley-Davidson Trike and 2017–2021 Harley-Davidson Touring models, or similar select M8 applications)
Bore Size: 4.250 inches (standard or big-bore style depending on configuration)
Head Gasket Thickness: 0.040 inches
Base Gasket Thickness: 0.014 inches

Material Construction: Multi-Layer Steel (MLS) featuring two outer Viton-coated embossed spring steel layers with a center steel layer.

Design & Features
Viton Coating: Outer layers are coated on both sides with Viton rubber to handle harsh sealing environments, high loads, and varying surface finishes.
Load Control Embossments (LCE): Promotes an even torque load across the gasket sealing surface, reducing bore distortion and improving piston ring seal.
Installation: Designed to go on dry (do not apply extra liquid sealants or silicone, as the built-in Viton layer handles the seal).

Specs

Product Name	Gasket
Type	Cylinder Head / Cylinder Base
Style	Standard Bore
Material	Viton / MLS (Multi-layer Steel)
Bore Size	4.250"
Thickness	0,040" / 0.36 mm / 0,014" / 1.02 mm
Units	2 Pack
Riding Style	Street