Sealey Tyre Rack Extension Two Level 200kg Capacity Per Level STR600EExtension unit for Model No. STR600. Supplied as three pairs of cross beams and a single upright in order to reduce cost when looking to build multiple tyre racks. Stores up to 26 tyres, 13 per level, with a total capacity of 400kg (200kg Level) when used with Model No. STR600. Stores up to 26 tyres, 13 per level, with a total capacity of 400kg (200kg Level) when used with Model No. STR600. Specifications Detail Extension unit for Model No. STR600.