Engaging surfaces arrangement for a pivoting detent joint

A mirror assembly having a pivoting detent joint, comprising:

• a carrier base for mounting to a vehicle;
• a support arm carrying a mirror head and being pivotally mounted to said carrier base;
• an arm detent ring carried by said support arm;
• said arm detent ring defined by a continuous circular arrangement of a combination of arm locking teeth and alignment teeth, wherein any one of said alignment teeth occupies a larger portion of said arm detent ring than any one of said arm locking teeth;
• a base detent ring carried by said carrier base;
• and,
• said base detent ring having a complementary arrangement to said arm detent ring and defined by a continuous circular arrangement of a combination of base locking teeth and alignment channels, wherein any one of said alignment channels defines a portion of said base detent ring able to receive at least any one of said alignment teeth;
• whereby said arm locking teeth of said arm detent ring engage said base locking teeth of said base detent ring in a releasable interlocking engagement only when all of said alignment teeth are received into a complementary alignment channel so that positioning of said support arm relative to said carrier base is limited to specific orientations.