A mount with DV (swivel) top and "new style DV" connection underneath.
The mount is for use with leads fitted with the "new style" DV elbow plug which has a male pin on it (see additional picture). The mount is also supplied with a small "pin" (see bottom of picture) which allows you to use it with a lead that has the "old style" DV plug on it.
By adding a "3/8 to DV adapter" (C52) you can use this mount to angle the antenna (eg for mounting on a sloping surface).
The mount has a good rubber seal and the use of a DV plug means the coax comes out at a right angle (ie parallel with the body) rather than straight down.
Remember to order a wingnut/bolt to go with it if you need one!