Single block with two pulleys in Sliding, allowing the attachment of up to 4 rubbers for scaled inverted systems. This is a specially designed pulley system for neatly containing, organising multiple bands and allowing easy access for interchange of rubbers in invert-pulley roller spearguns.

They are openable and light weight. The body is laser cut from quality Titanium and the pulleys are made from solid Delrin, with Sliding bearings, or with Ceramic bearings. Sliding bearings allow for smooth rolling wheels and easier loading. Ceramic bearings allow a longer life, along with less resistance. 

These are useful to simplify attaching multiple bands and eliminate the added weight, length and complication of shackles.