Hello again from GeetarGizmos. We're very happy to offer our slotted Cow Bone nut specially shaped for the Gibson J-45 acoustic guitar.  Drops right in as a direct replacement for the budget plastic nut.  

Hand ground and sanded from cow bone blank and round-slotted for perfect string placement. Handmade in our USA shop to fit your guitar. 1.72" long, .37" tall, .19" thick.  Shipped immediately with full postal tracking.

"Great service! Even made a custom adjustment for me. Looks great!" 

"quick shipment, item in good condition, thank you" 

"Wonderful - thanks!" 

"It came today! looks good and it'll work well! A++++++++++" 

"Great tone improvement!"