ikig Horns V4008K-2C Loud 139 Decibels Chrome Four Trumpet Air Horn Kit With Dual Direct Drive Air Compressors Sound Output:139 decibels Horn Construction: 4 metal chrome plated trumpets Dual heavy duty direct drive air compressors (no air tank needed) Tumpets sizes: 13-3/4", 11-1/2", 9-1/4", 7-3/4" with 3-3/4" bell diameter each Ideal for Boats, RV's, SUV's and Trucks, and many more applications.