This is brand new, never mounted, and removed from the packaging only once--to create this listing! The whole setup sans bottom bracket barely tips the scale at 600 grams!

The mid-compact chainring configuration is 52/36t, and the crank arms are 172.5mm. I am of course including the bottom bracket (also brand new and still in the package). Lastly, I have the 9100 chain and cassette (sized at 11/28), both also brand new, and can negotiate a price on these as well after the sale. 

Thanks for looking!

Some additional info from around the web: 

Just like every other iteration, the new 9100 crankset offers an improved stiffness-to-weight ratio. A key factor in this is the enlarged crank arms and outer chainring. Additionally, Shimano’s asymmetric approach takes a further step with closely analyzed and focused load points of the four-bolt design. This comes with a seven-gram drop in weight.

These new chainrings are said to have a new tooth profile that’s better suited to wider gear ratios. Not including the bottom bracket, crankset weight is claimed at 609 grams (50/34T).