"Well as per the title this is larger than expected - I was hoping for something the size of a stop cock cover but this is about 4 times bigger in surface area. It is missing a lot of bits for fitting to an earth rod:- firstly it has a large hole in the bottom which needs a seal plate and that then has the rod seal assembly. Disappointing. The access pull key holes accept the allen screws supplied but do not seal to the base so would eventually fill the rod end chamber with water - bizarre. In spite of the supplier being called Green brook the product is moulded with FURSE a Thomas and Betts company."