25 Well Nuts Auveco 16253 GM OEM : 342271 Car Truck SUV Van ATV Luggage Racks25 Well Nuts With the Neoprene Materials of the Well Nuts; with Captive Brass Nut, you are sure to get a good quality product!! The Dimensions of the Well Nuts : Thread Size : 1 4 20 Grip Range : . 250 . 457 Head Diameter : . 635 Overall Length : 1. 051 Shank Length : 1. 000 Shank Diameter : . 500 Head Thickness : . 051 Hole Size : 1 2" The Well Nuts Fit The Following Manufacture OE Specs : O E = Original Equipment GM : 342271 O. E. M. Application of