The Press-O-Film X-Coarse Grade (1.5-4.5 mils / 38-115 microns) Replica Tape, Roll is used with a gauge to measure the surface roughness ("profile") of blast-cleaned steel. Testex Press-O-Film Replica Tape offers a unique replica technique and with a simple snap gauge will allow you to take accurate, low-cost blast-surface profile measurements. Testex makes surface replicas easy to obtain and produces average maximum peak-to-valley readings that ensure optimum blasting effectiveness. Replicas can be retained for future needs.The accuracy of Testex measurements is due to an innovative two-level film that can produce virtually exact replicas of the abrasive blast surfaces. The film is available in three different thickness grades to cover the most common range of blast profiles.Measurements can be taken in locations that are not possible using conventional stylus devices, e.g. internal pipe diameters and grooves, etc.Easy to use, remove the protective paper from the tape and place firmly on the blasted surface. Apply moderate pressure with the Burnishing Tool over the circular cut-out in the tape. Remove the tape. The replica is now ready for measurement using the Snap Gauge.