Wattmeter Single Socket Unflanged 1500 W to 60 KW15/30/60 ScaleModel 81315-AWattmeter with 3-1/8″ Single Socket Unflanged Recessed Line Section.The 81300-A series of High-Power Directional RF Wattmeters are designed to measure RF power in 50-Ohm 3-1/8″ coaxial transmission lines.To use the Wattmeter, simply connect it between the transmitter and antenna or dummy load and plug in the appropriate measuring element. The RF power is directly displayed on the 4-1/2″ triple scale meter.Several different models are available with either 5/10/25 scales or 15/30/60 scales. The external Line Section can be used up to 200-feet from the meter with the permanently attached DC cables (10-foot normally supplied). The meter unit is protected by a rugged, shock-proof housing. For added convenience, two sockets for storage of additional measuring elements are located on the back of the unit.The use of a rugged shock mounted meter with a mirror-backed scale along with superior taut band technology, provides reliable and accurate readings, and also satisfies both the US Navy and Canadian standards for bounce and vibration. This is your assurance of complete accuracy.Your confidence in the quality and dependability of the 81300-A series of Wattmeters is assured with the Coaxial Dynamics Two Year Limited Warranty. Shock Mounted “Taut Band” Meter 4-1/2″ Mirrored Scale Uses Standard Gold Plated Plug-In Elements Two Year Limited Warranty