Useful rectangular-bezel non-magnetic APIs, I think were from an RCA product based on one of the seven-digit codes on the units. Early 1970s. About 4-15/16" x 2-7/8". 

Good working condition, no cracks or damage. The scale card is a bit more faded on one than on the other, and its ballistics are a little bit stiff, but it still responds. 

Each weighs around 12 oz. No additional hardware included.