Both FR-5 and FR-6 needle injectors are basic instruments used for Ryodo-Raku treatment. Smooth, painless needle insertion is possible with these injectors. The FR-5 and FR-6 accept only Japanese metal handle needles of No.5-8 gauge. Turning the knob counter-clockwise locks the needle. Autoclavable.FR-5 for 50mm length needlesFR-6 for 60mm length needle