A control handle for a surgical tool, e.g., an irrigated ablation catheter for use with a fluid side arm, has a housing defining an interior cavity and having a port through which the component can extend into the interior cavity. The housing has a detachable plug covering at least a portion of the port and being at least partially surrounded by a recessed groove to facilitate detachment of the plug from the housing. The recessed groove may be formed on an outer surface of the housing and there may be a second recessed groove on an inner surface of the housing generally tracing the first groove. The plug may also include a hinge to allow the plug to be arranged at an angled position relative to the housing without being fully detached from the housing.