Lextek S/Steel Silencer. Lextek S/Steel Downpipe. 1x Lextek Exhaust Assembly Paste. 1x Lextek Stainless Steel Header. 1x Lextek Lambda Sensor Blanking Bolt (Brass) M18 x 1.5mm. About Lextek. Motorcycle exhaust pipes are fitted with silencers at the end to reduce the noise from the engine.