First off I am impressed with speed of the order I placed for several of your Clipdraw products. Ordered the stuff on the 18th of March and it arrived today, the 22nd. In regards to whether or not the Universal Clipdraw will work on the Ruger SP101… I can say it will. I decided to try it and it seems to fit and work quite well. Will test it by wearing for a week or so and probably order some more of the Clipdraws. These things are very nice for use here in Florida due to the hot climate causing problems with clothing concealing holsters and such. I look forward to doing more business with you. Best regards.