This Fender reverb unit is a 4 spring reverb with long decay (2.75 - 4.0 seconds). It is 8 ohm with RCA input and output jacks. This unit was used on many of Fenders reverb amps including, Prosonic, Showman 50, '94 Twin, Custom Vibrolux Reverb, Custom Vibrosonic, Protube Series, '63 Vibroverb, '65 Twin Reverb, '65 Deluxe Reverb, '65 Super Reverb, '65 Twin Custom, Vibro King, Dual Professional, Super Sonic Series,, '64 Vibroverb, Princeton, '65 Princeton (1991 to present). Measurements are 16 3/4" wide x 4 1/4" deep and 1 1/2" high. Fender warranties its parts for one year. Part number 0064063049.