Metolius - Rock Rings 3DMetolius Rock Rings are a portable training device designed for pullups and finger strength training on the move. A large jug on top allows for easy warm up before a training session, while the three different sized edges are ideal for building up finger strength. The kind texture allows for full training sessions without fear of ruining your skin and the resin means they won't be eaten away in minutes if you have a termite 'issue'.