A button-sewing foot is for attaching a button; it is a different accessory from the buttonhole feet covered in the Janome buttonhole-foot guide. Janome describes this foot as having two bars that attach to the foot shank for added stability and a textured rubber sleeve that holds a button in place.
Janome America lists three variants with separate part numbers and model groups.
A 9 mm or 5–7 mm label alone does not establish fit, and Janome does not say that these lists cover every model revision or market.
9 mm variant — part 859811008#
Models shown: Horizon Memory Craft 8900QCP Special Edition; Horizon Memory Craft 12000; Horizon Quilt Maker Memory Craft 15000; Memory Craft 9900; Horizon Memory Craft 8200 QC; Horizon Memory Craft 15000 V2; Horizon Memory Craft 8200QCP Special Edition; Skyline S7; Horizon Memory Craft 14000; Skyline S5; Horizon Memory Craft 9400QCP; Skyline S9; Memory Craft 6700P; Skyline S6; Horizon Memory Craft 9450QCP; Memory Craft 6650; Memory Craft 9850; Continental M7 Professional; Continental M17; Continental M7 Quilter’s Collector Series; Continental M6; Continental M8 Professional; Horizon Memory Craft 9410QC; Horizon Memory Craft 9480QCP; Skyline S7 Anniversary Edition; Skyline S6 Anniversary Edition; Memory Craft 9850 Limited Edition; Continental M6 LBQ; Skyline 8.
The page also shows “Button Sewing Foot” in this variant’s list. It does not identify a machine, so it is not counted as a compatible model.
5–7 mm variant — part 200136002#
Models shown: Memory Craft 11000 Special Edition; Memory Craft 6600P; Memory Craft 6500P; Schoolmate S-3015; Classmate S-750; 712T; Jem Gold 660; Jem Platinum 760; Sewist 500; HD-3000; Magnolia 7325; Magnolia 7318; MyStyle100; DC1018; DC1050; Hello Kitty 18750; Magnolia 7330; Magnolia 7360; DC2013; DC5100; 8077; 49018; DC2012; DC2014; DC4030P; JW7630; Schoolmate S-7330; 8050; MOD-30; MOD-50; MOD-19; MOD-15; Skyline S3; DC2015; MOD-11; JW8100; MOD-100Q; AMH M100; MOD-200; M7200; M7050; 6100; 6050; M7100; 3160QDC-B; 2030QDC-B; HD-3000 Black Edition; 4300QDC; DC2019; Sewist 780DC; Sewist 740DC; Sewist 721; Sewist 725S; NPCF50; 3160QOV; 3160QDC-T; 4120QDC-B; 4120QDC-T; 5300 QDC-T; C30; TM30; MOD-100; HD5000BE; HD-5000; 2030DC-T; 5124; 6019QC; 6125QC; 6260QC; MS5027PR; Memory Craft 3000; Memory Craft 4900QC; Memory Craft 5200; Schoolmate S-3023; Sewist 525S; Sewist 709; TM16; TS100Q; TS200Q; C30W; Horizon Memory Craft 7700QCP; MO200; 2030DC-G; 3160QDC-G; 4120QDC-G; 5300 QDC-G; TM50; TM200; Skyline S3 Anniversary Edition; 5300 QDC LBQ; G+I Computerized Sewing Machine in Sable; G+I Computerized Sewing Machine in Misty Blue.
The page also shows “Velvet Foot” in this list. Janome does not explain the entry, so it is not treated as a machine model.
FL variant — part 200131007#
Models shown: Hello Kitty 11706; HD-1000; 2222; 2212; 2206; 3128; Hello Kitty 13512; Hello Kitty 14412; Hello Kitty 15312; 41012; 128; Hello Kitty 15822; HD-1000 Black Edition; SUV1122; Arctic Crystal; Sew Fresh; 234; 1522PG; 311PG; 1522BL; 1522RD; 1522DG; 108; Pink Sorbet; Blue Couture; Lovely Lilac; Signature Charm; Purple Majesty; Cat Fancy; HD-2200; Toile Romance; Wisteria Promenade; 1522BG; 1522SG; 1522SP.
Janome uses the label FL for this variant; the product page does not expand that label or provide installation, button-size, stitch, or clearance instructions. Confirm the exact model revision, local market, part, and manual before buying or sewing. Use only the button attachment settings and clearance checks specified for your machine.