This Tower Power Starter is used to Start Radio Controlled Car, Boat, Helicopter or Aircraft Engines up to .90 Cubic Inches. FEATURES: Deluxe Aluminum Starter Cone w/V-groove and rubber insert. Self-adjusting carbon brushes and finger guards for safe starts. An easy-press start switch requires very little finger pressure. (THIS STARTER IS NOT PANEL READY) see comments Two year limited warranty through Hobby Services beginning at date of purchase INCLUDES: One Tower Power 12V Deluxe Starter w/Alligator Clips REQUIRES: 12V DC power sorce such as HCAP0800. SPECS: Length: 6.75" Cone inside diameter: 1-13/32" Width : 2.75" outside diameter: 1-3/4" Height: 3.75" Shaft diameter: 5/16" COMMENTS: For Rubber Insert, Hobbico Torqmaster 90 Insert, HCAP3315, will work For Aluminum Cone, use TOWP0505. 10/25/93eke ir/jl updated4-5-2kh updt jxs 4/15/03 updt jxs 05/21/10