The Sabelt Silver Endurance 6 Point Harness, part number 210A622SD2F, is a clip-in 6-point competition harness approved to FIA 8853-2016. Shoulder and lap webbing are 2 inch. Aircraft-type buckle. HANS specific. Available in black, blue and red.
Endurance designation in the Sabelt range indicates a harness configured for longer events, with an aircraft buckle as the defining difference over the standard Silver 2×2 clip-in (210A622SU2F, £337). An aircraft buckle is a flat plate rotational release rather than a T-bar clip: some drivers and co-drivers in long-distance racing prefer the flat plate for the speed and ease of operation when strapping in repeatedly over a 6, 12 or 24-hour event, or when a marshalling crew needs to release the harness quickly.
Silver series hardware and 2×2 webbing keep the weight controlled for saloon competition. HANS specific means the shoulder geometry is configured for a HANS device.
At £389 this is £52 more than the standard Silver 2×2 clip-in. The extra cost is the aircraft buckle. If the clip buckle in the standard version works for your use case, that is the lower-cost option. If you want the aircraft buckle for endurance or marshal-release reasons, this is the appropriate choice.
Above this in the Silver range, the Silver LPM (2170068, £784) uses the same 2×2 aircraft buckle clip-in HANS specific specification but is built to Le Mans Prototype cockpit requirements.
