A pair of cylindrical weights for use with Neolt Parallel Motions. The weight has a duct running through the centre through which the wire is pushed. The wire is locked by tightening hexagonal bolts (allen) threaded through the weight. Sold as a pair. Can be used on other makes but remember these are "counter" weights designed to counter balance the weight of your parallel motion ruler and may not balance a very heavy ruler.
Royal Mail Packet