21/31" (17mm) Hole Size Top Head Size: 20mm x 30mm Stem Length: 12mm Black Nylon With Sealer Rocker Panel Moulding Clips Compare with: Auveco #, 20884, G.M. # 11561491, # 15872008, Car Pak # 99-8622, 998622, Barnes / Kar # 99-8622, Disco # 10651PK, 10651B, Crest / Midwest # CRX19850, Kent / Lawson # KT14291, Winzer # 502.3536, Wurth # 150120884, S&R # 421385