diff --git a/htdocs/gfx/svg-defs.svg b/htdocs/gfx/svg-defs.svg
index 1cfe95d0..9579f00f 100644
--- a/htdocs/gfx/svg-defs.svg
+++ b/htdocs/gfx/svg-defs.svg
@@ -27,5 +27,7 @@
         <g id="noise-reduce" fill="#fff" stroke-width=".767"><path d="m 36.606611,74.237282 -9.008789,0 L 11.11833,30.951149 q 0.659179,3.164062 0.659179,4.96582 l 0,38.320313 -10.0195308,0 0,-68.7744143 9.0087888,0 16.479492,42.4072263 Q 26.58708,44.706032 26.58708,42.904274 l 0,-37.4414063 10.019531,0 0,68.7744143 z"/><path d="m 80.200361,74.237282 -10.722656,0 L 58.139814,42.28904 q 0,0 0,-6.196289 l 10.107422,0 0,-21.796875 -12.963867,0 0,59.941406 -10.283203,0 0,-68.7744143 27.290039,0 q 6.196289,0 6.196289,6.3281253 l 0,25.004883 q 0,4.350585 -2.944336,5.625 -1.582031,0.659179 -6.679688,0.659179 l 11.337891,31.157227 z"/></g>
         <g id="disabled" fill="#fff" stroke-width=".767"><path d="M 59.826868,-0.58229828 28.318079,81.155983 l -7.602539,0 31.376953,-81.73828128 7.734375,0 z"/></g>
         <g id="tuning-step" fill="#fff" stroke="#fff" stroke-width="4.0"><path d="M 3.75,67.704399 22.378472,40.00535 3.75,12.306311 Z M 76.25,12.306311 57.621528,40.00535 76.25,67.704399 Z m -18.628472,27.699039 -35.243056,0"/></g>
+        <g id="left" fill="#fff" stroke="#fff" stroke-width="4.0"><path d="M 55,15 55,65 15,40 Z"/></g>
+        <g id="right" fill="#fff" stroke="#fff" stroke-width="4.0"><path d="M 25,15 25,65 65,40 Z"/></g>
     </defs>
 </svg>