Product Info for UM Tactical IWB Holster UM Tactical's IWB Holsters are handmade and constructed of 4332 Boltaron. Boltaron has a much wider temperature range before cracking under arctic cold or deforming under high heat, it also has an ultra high impact resistance over Kydex. These holsters are extremely comfortable and have an adjustable 0-15 degree cant. Our holsters are made in-house resulting in unmatched quality control, form and fit. Specifications for UM Tactical IWB Holster: Fabric/Material: Boltaron Holster Type: Inside the Waistband Holster