The instruction manual can be viewed here
Smaller than the Lenz Silver Direct in every dimension
This deocder comes with an additional purple wire to add a 4th function.
Pin one is located by botton of the H on the decoder. There is also a number 1# at the bottom of the letter on the plastic sleeve.
The Hattons decoder range may not work with Hornby branded controllers. They should work with any other controller and have been tested with all other major brands.