This kit p/n 100-SPARES-F includes (1) spare microsyringe assembly, (1) pack of 6 Viton O-rings for the microsyringe assembly, (4) replacement 22g reusable 304 stainless steel dispensing needles, (1) pack of 10 disposable 22g 304 dispensing needles, and (1) replacement light bulb for fiber optic illuminator system. Recommended for all U, F and G Series ramé-hart goniometers and Tensiometers. Save $35 compared to purchasing parts separately. Note: 22g reusable needles can be substituted for any size 8-30g. Specify sizes in the comments box at the end of the ordering process. Order p/n 100-SPARES-F for any current generation U4, U1, G1, F3, or F4 Series system or any legacy F1 or 00 Series system. If you have an F2 Series system or Model 90, see the Complete Set of Spare Parts for Model 90.