GS-SRM. Small rail mount for up to 1' (2.54cm) diameter tube.Place the G clamp over railing & tighten so it is vertical to the rail. Best for stainless tubes or any other suitable rail of 1 inch or 2.54 cm diameter. If the clamp is left on a rail, remove the centre pin to avoid injury! To prevent any risk of the Gullsweep falling off in high winds, we strongly recommend using a Gullsweep retainer kit.