The Gitzo GS5321V100 Series 5 Systematic 100mm Half-Bowl Video Head Adapter is a tripod accessory that enables the use of any Series 5 Systematic Gitzo tripod (and series 4 aluminium tripods) with a 100mm half ball video head. These heads are designed for videography but they are also popular with photographers who use long telephoto lenses. The GS5321V100 is compatible with the safety catch feature of the updated Systematic tripod range, which offers secure, accident-proof support even when switching critical components. This model is made of aluminium and weighs 226 grams.