Maver s d umbrella arm the maver s d umbrella arm are high quality umbrella arms are great for fishing on hard ground or a platform when you cant get the spike of the umbrella into the ground the double brace is a huge improvement on a single arm it keeps the umbrella in the correct position even on very windy days days when a single arm would just keep moving around maver s d umbrella arm will fit most seat boxes 25mm legs 30mm legs 36mm legs black