These pouches fit an Altoids Tin and have a velcro closure with a velcro panel on the front for attaching patches (patches shown not included).  The material is a flexible nylon material but there is a Kydex insert in the back and they are bolted in place so there is no "slop" once they're mounted in place.

These fit Kydex Scout Sheaths for larger knives like: BK2, BK7, ESEE-5, ESEE-6, Tracker etc.  I can make a Scout Sheath for smaller knives but it will extend (stretch) the dimensions of the sheath (upon request).