Kadee Quality Products
Standard Head All-Metal Whisker(R) Self-Centering Knuckle Couplers 2 Pair

#146 Long (25/64") Centerset Shank
Walthers Part # 380-146, p. 243 Walthers 2012 HO Scale Reference
HO scale, $4.27, currently in stock at Walthers
This product is on-sale today for $3.98