SGL manufacture a range of glass-lined agitation devices, impellers and paddles, including Anchor-type, Paddle-Type and Impeller-Type as shown below.
Anchor Type
The Anchor-type agitation device gets its name because of the similarities in shape to a ships anchor, as shown.
SGL's AE-Reactor is supplied with this type of Anchor agitation device as standard.
The Paddle-type agitation device is probably the simplest form of any agitation methods, and comprises of at least one, typically three, radially extending straight arms from a central shaft, as shown. 
SGL also manufacture the Impeller-Type of agitation device, which typically shares similarities with the Paddle-type albeit the radially extending arms are curved, as shown below.