Proudly Made in the USA, the Rectangular Current Transformer Model RT2020 is designed to fit over bus bars. There are fully encapsulated for indoor and outdoor applications. It's rectangular design with a window diameter of 2.00 x 2.00 and a standard 1-amp secondary. Others available. The RT202 terminals are brass number 10-32 UNC with one flatwasher and lockwasher. CSA Optional. This model weighs in at approximately 1lbs.