The Exped Bivybag Lite Ventair/PU is a lightweight bivvy sack that offers a simple, close-to-nature shelter for your sleeping bag. It’s designed to keep wind, rain and ground moisture out while you sleep under the open sky, without the bulk and complexity of a tent.

Constructed with a two-layer VentAir TPU laminate and fully taped seams, this bivy bag provides a 10,000 mm waterproof rating while allowing excess moisture to escape thanks to an 8,000 g/m²/24 h breathability. Inside, a recycled 70 D taffeta nylon layer with a 7,000 mm water column rating adds further protection against dampness. At 230 × 90 × 80 cm and just 0.49 kg, it accommodates most mummy-style sleeping bags and won’t weigh down your pack. With a comfort range down to around 5 °C, it’s well suited to late spring through early autumn outings.

Water column ratings (measured in millimetres) indicate how much water pressure the fabric can withstand before leaking, so 10,000 mm handles steady rain. MVTR (moisture vapor transmission rate) describes how much moisture vapor the fabric lets through—8,000 g/m²/24 h helps reduce condensation inside. The TPU (thermoplastic polyurethane) laminate bonds a thin waterproof membrane to the fabric for strength without heavy bulk, and all materials are PFAS-free to minimize environmental impact.