Extremely strong Round Servo Arms for the Monster Gearboxes. Made from 1/4" thick ABS plastic. Diameter is meaasured across center hole edge to edge. Four equidistant outer holes are 1/8". However, they can be easily drilled to a larger diameter for other applications or linkages. Note: Use these with the Robust Turntable (and a Servo Hub) if you need a larger table! 1 Each Monster Arms (round) SASMAR$9.99Diameter: No-Preference4"6"(+2.00)8"(+4.00)10"(+6.00) Copyright © 2003-2009 E-Clec-Tech. All rights reserved. All other materials and logos are copyrighted by their respective owners, or companies.