The Leatt ADV 5.5 ThermaFlow is a slimline insulation jacket designed to layer under riding gear or wear off the bike. Its double-knitted, wind-blocking softshell combines graphene-infused 3D block fleece backing with a fitted body and slim stretch forearms to reduce bulk beneath an outer jacket.

Construction and Insulation

• Double-knitted wind-blocking shell with graphene-infused 3D block fleece backing.
• Leatt describes the graphene insulation as designed to redistribute heat from warmer areas across the fabric for more even thermal management.
• Leatt describes this as the thinnest insulation jacket in its ADV mid-layer line.
• Lightweight four-way-stretch Ripstop reinforcement at the elbows and seat area for durability.
• DWR C0/20 dirt- and water-repellent treatment; not described as a waterproof jacket.
• Fitted body and slimline stretch forearms for layering.
• Overlocked seams with internal taping for comfort.

Pockets, Adjustment and Details

• Two handwarmer pockets with YKK zippers.
• Key loop in a pocket.
• Concealed shock-cord hem adjustment.
• YKK main zipper.
• Reflective visibility detailing.
• Garment hanging loop.

Supplier-Listed Material Claims

• UPF 50+ rating.
• Bluesign-approved materials.
• Supplier states the product meets the latest USA PFAS standard; no specific standard or test documentation is identified in the supplied listing.

Color, Sizes and Additional Details

• Color: Midnight Blue.
• Sizes: S, M, L, XL, 2XL, 3XL and 4XL.
• 5-year warranty, subject to Leatt's warranty terms.
• Plastic-free packaging.