Swift Blocker Mini 27The most economical model, the Mini 27 produces the same size blocks as the 72 but in a smaller footprint for growers looking to use smaller sized trays or need less blocks. Total footprint of the blocks are 4. 5 by 14. Simple and hand operated, growers have the option of having a smooth or dimpled soil block through removable dibbles. The finished 27 soil blocks are approximately 1. 5 in size.