Arkon RM38352XMAMPSSH Robust 5.4 inch Metal AMPS Mount with Security Hardware - 38mm (1.5 inch) Ball Compatible (sku 55957)5. 4 inch mount features heavy duty 38mm (1. 5 inch) ball compatible Robust mount shaft arm Compatible with devices with 4 Hole AMPS pattern Durable mount is ideal for commercial use Included security hardware helps prevent theft RM38352XMAMPSSH is a 5. 4 inch heavy duty 4 Hole AMPS drill base mount featuring security hardware that can be easily installed to prevent theft. Part of Arkons Robust Mount Series, this mount is ideal for commercial vehicle