Greatbatch Stiffer Coaxial Micro-Introducer. Model #/ Name: 10904-001 Stiffer Coaxial Micro-Introducer 4FR; 10904-002 Stiffer Coaxial Micro-Introducer 5FR. || The radiopaque Stiffer Coaxial Micro-Introducer (Figure 1) consists of a dilator and sheath, available in 4FR and 5FR. The inner dilator includes a stainless steel stiffening hypotube. The Coaxial Micro-Introducer is indicated for percutaneous introduction of up to a 0.038 in. guidewire or catheter into the vascular system through an initial puncture of a 21G introducer. The device is sold to customers || in a bulk non-sterile configuration.