Recently, I purchased a set of extension tubes made by Fotodiox (non electronic). Initially I was a bit hesitant due to their price – they were three times more costly than another brand. But I decide to order that set after reading in the review that this set is made from metal. And they are made from metal.
The set fits snugly on my Canon 700D and am happy with the results, even though many of the photos are not up to the mark (as I am hand holding the camera during photography). Also I am yet to master the small depth-of-field.