This is the Eagle Tree R/C Dual Axis G-Force Expander. It is used with your data recorder to measure acceleration on two axis. **Will not function with the new V3 Elogger.** FEATURES: G-Force expander INCLUDES: G-Force expander Instruction sheet REQUIRES: A plane that is large enough to accomodate the extra equipment and a data recorder to hook it up to. SPECS: Length: 1-1/2" (38mm) Width: 3/4" (19mm) Thickness: 1/4" (7mm) thickest part Weight: 0.18oz (5g) COMMENTS: If you need further assistance go to www.eagletreesystems.com or email to support@eagltreesystems.comEagle Tree SystemsPart ETRGFORCE-38