Design: One - 5 ½ inch flat treatment surface that produces two ninety-degree treatment edges. This instrument can be used at a 45 or a 90-degree angle. Use: Calfs, glutes, hamstrings, quads, neck and spine, shoulder, IT band and larger muscle groups. If more treatment pressure is needed after scanning, use the smaller surface on SASTM #5 instrument or the point on the SASTM #4 instrument. Can be used for the evaluation and treatment of calfs, gluts, hamstrings, quads, neck and spine, shoulder, IT band and large muscle groups that would take longer to evaluate and treat with SASTM #1, #2, or #3 instruments. SASTM Instrument Comparison: SASTM #6 instrument produces more evaluation and treatment surface than SASTM #1, #2, #3, #4 and #5 instruments. The 5 ½ inch treatment surface decreases evaluation time and allows for treatment of larger muscle groups. Smaller surfaced SASTM #1, #2, #3, #4, and #5 instruments are recommended as more pressure is needed.​ Handcrafted and produced in the USA ​ *Certification, emollient, case, and accessories sold separately.