I've used this plastic key clip on a nylon belt loop for at least 15 years (law enforcement supply shop)...cascading split rings allow everything to slip into rear pocket... just got the E05, and am trying it out...I've had the P38 since 71/72 and now it's a "BTDT" thing.... as far as an additional belt pouch, depending on what you want to carry... an intermediate sized multi tool like the LM Juice S2 and a cr123 light like the Tac Pro 1L fit along with a section of hacksaw blade, small ferro rod, needle, safety pins, tweezers, and petroleum cotton ball in straw into a generic large multi tool pouch... alternatives to the light and multi tool like the Vic Farmer and Bic allow you a little more room