Hello Marc123...Try Ripoffs brand which is what I have been using for years.
Use the Flashlight table at ripoffs.com/flashtable. There are several tables/charts/listing by brand, size etc.
Brightguy.com is an excellant dealer to buy from. You can call or E-mail Greg at Brightguy. He is very helpful as to helping you with what you might need.
This is where I bought my first few flashlights several years ago when the "flash bug bit me"
There are more than on model for your light so I mention the table/chart so you can pick what you feel suits you best....I have never had a problem with either Brightguy.com or any Ripoffs Models...Good Luck....William
Opps....I forget I don"t have that model Dereelight yet, but I do know that Ripoffs brand holsters for Surefire P6, C2 will fit your Dereelight