How to check which one (SK1215 or BK1216) will fit my door?

There are many steps and details to verify in order to select the right handle set to replace the old handle set. 

We only have surface mount handle sets, and they are not compatible with mortise handle sets.

First, remove the old handle set from the door.

Second, Check anchor screw, measure distance, and count the posts on the old outside handle, choose the matched one (SK1215 or BK1216).

Third, double check how the old deadbolt was mounted.

If it was mounted with two machine screws to the outside handle posts, then the BK1216 should be selected.

If it was mounted with two tapping screws to the door inside surface, then the SK1215 should be selected.

Fourth, measure the existing hole patterns on the old door, select the matched one. This is a double check step.

SK1215 hole pattern:

BK12126 hole pattern: 

Please check the respected product page for more info.