The aerial base No.10 Mk.2 is one of two aerial bases used with the 'A' set of the No.19 wireless set, so pre-Larkspur. (The other is the earlier No.8 aerial base. Larkspur series uses the No.28 aerial base mated to a tuning unit).
Common on WW2 vehicles and well into the post-war period, especially in Australia where the No.19 set was not fully replaced in service until the mid-1960s, (or even later in some CMF units).
In AFVs, the No. 19 set was often paired with a No.88AFV set.
Hard to find in good, usable condition these days.
Mike