L148-9 – Heavy Duty Flange-Blank. Type L148 is a structural base fixing used to fix down guardrailing and balustrading. This fitting is available with either 2 or 4 fixing holes which are sufficient diameter to give a good fixing with either a mechanical or chemical anchor. The two socket set screws give greater stability to the upright. It is recommended that fixing holes be in-line with the applied load.