Instructions on installation of the scope mount is provided in the packaging. All Henry scope mounts accept Weaver style detachable 1" top mount rings (rings not included). Picatinny-style rails in particular accept Weaver or Picatinny style top mount rings as well as red dots. Screws are included with the mounts.
 
Model # HL-RSMP
Fits all H001, H002 and H003 models
 
The receivers on the H001, H002, and H003 series rifles have a 3/8 inch dovetail running along the top of the receiver. You can use the HL-RSMP Picatinny adaptor listed on this page to convert the 3/8 inch groove to 1 inch slots for if you wish to mount a red dot optic, or Weaver/Picatinny rings for a scope. 
 
Measures out at approximately 4 1/2" with 11 adjustable slots.

If you are putting this rail on the H002 U.S. Survival rifle, they will have to be removed before disassembling back into the stock.
If preferred, you can use 3/8 inch rimfire rings which attach directly to the dovetail