Simms 37822 M3 BOA Field Repair KitIncludes M3 replacement knob and wire lace for easy lace system replacement in the field. For use with our RiverTek Boa Boot and RiverTek Boa Boot Felt.For 1st GENERATION RiverTek Boa Boots please order M3 BOA FIELD REPAIR KITFor the G4 Boa Boot, please order the G4 Boa Replacement KitTo Verify which RiverTekâ Boa Boot you have: Look inside the boot on the tongue label where the size is marked. 2nd Generation boots will state "Boa M2 Reel" and the lace length, 1st Generation boots state only "Boa" and lace lengthFeaturesIncludes M2 replacement knob and wire lace for easy lace system replacement in the fieldS/M lace length: 100 cm, fits boot sizes 710L/XL lace length: 110 cm, fits boot sizes 1114More information on the Boa Lacing System