It is a Blackhawk by Proto 6 Piece Magnetic Nutsetter Set - SAE
It is a Magnetic fractional nutsetter
It contains sizes 5/16 through 3/8

Technical Details

Size (LWH): 4.5 inches, 3.8 inches, 1 inches
Product Details
Product Dimensions: 4.5 x 3.8 x 1 inches
Shipping Weight: 0.65 pounds (View shipping rates and policies)
ASIN : B00D05CH08