CamDive 8"/22cm Aluminium 1"Ball and YS Head Adapter, Arm for Underwater Strobe/Housing Construction: Corrosion-resistant aluminum alloy (hard anodized body) Length: 8.8"/22.5cm Weight : 80GR Ball size: 1"/25mm Package includes: 1 x 8.8"/22.5cm 1"ball & YS head mount arm