The Robits Spring Extend Kit is a simple method to add linear motion to your robot. Description What's in the Box? Documentation This kit uses ball bearings to provide a smooth extension. The constant force spring extends a tube in one direction and the spool/cable retracts the tube in the other direction. **Note** The following components are NOT included with this kit. 2 - 0.5 x 0.5 Robits Tubes 1 - NeveRest Orbital Motor 1 - 6mm D to 375IN Hex Adapter (am-3444) Included Items: 6 - 10-32 x 1.5 in. Socket Head Cap Screw (am-1014) 11 - #10 Flat Washer (am-1026) 2 - 10-32 x 0.75 in. Socket Head Cap Screw (am-1047) 3 - 10-32 x 2 in. Socket Head Cap Screw (am-1049) 2 - 10-32 x 1 in. Socket Head Cap Screw (am-1056) 13 - 10-32 Nylock Jam Nut (am-1063) 4 - M3-0.5 x 8 mm Socket Head Cap Screw with Thread Patch (am-1500) 1 - 0.450 in. ID 0.500 in. OD 0.500 in. Long Aluminum Spacer (am-1699) 5 - 0.194 in. ID 0.375 in. OD 0.250 in. Long Nylon Spacer (am-1700) 1 - Power String, 1.4MM, 100' Spool (am-3159) 1 - 0.5 in. Wide 30 in. Long Constant Force Spring (am-4666) 8 - 5 mm ID 13 mm OD Shielded Bearing (695ZZ) (am-4724) 4 - Robits 2 x 4 Plate Gusset (am-5006_2x4) 2 - Robits 150° Angle Gusset (am-5010_150) 1 - Robits Motor Mount Bracket (am-5012) 1 - Robits Spool (am-5027) 1 - 0.194 in. ID 0.375 in. OD 1.000 in. Long Nylon Spacer (am-1696)