Singer's model 9970 fact sheet lists Class 15 bobbins among the machine's standard accessories. Use that exact model and class as a starting point, then confirm the replacement reference and material before ordering.
For presser feet, read the specific item's applicability rather than relying on a machine-family name. A supported accessory on one Singer model does not automatically establish support on every model with a similar number.
Keep bobbin class and material together
Class 15 and Class 15J are separate designations. Singer's bobbin guidance also distinguishes metal and transparent versions. Do not substitute a different class or material because an online photograph looks similar.
The 9970 fact sheet gives the class; use the machine instructions and an exact-item model match to finish the replacement check. Keep a known-correct bobbin as a labelled sample if you have one. Confirm the current offer's reference and quantity separately from the number originally supplied with the machine.
A bobbin holder, cover and bobbin are different parts. If something is damaged, identify the actual component before ordering. Photographs of the part in place and any readable reference can prevent an otherwise plausible but incorrect purchase.
Read presser-foot lists at component level
Singer's Sewing Machine Presser Foot Kit (SKU U2-SU5-021) specifically names 9970 for its blind hem, gathering, narrow rolled hem, overcasting, straight stitch and darning/freehand components. Use the exact kit reference and each component's instructions when considering those options.
The same kit's walking foot is not listed in that model group. Separately, Singer's 9970 fact sheet lists an even-feed/walking foot among the original standard accessories. Those are different claims about different supplied items; neither establishes that every retail walking foot fits.
When replacing a missing foot, identify the original reference or a separately supported replacement. Check the mounting arrangement, holder, any adapter and permitted stitches. A label such as “snap-on” describes an attachment feature, not a complete compatibility answer.
Choose accessories for the project
For a garment hem, start with the intended hem method and a supported foot. For gathering or freehand work, review the specific component's setup before buying it. Make a small sample in the project's fabric and thread before committing to the finished piece.
With any specialty foot, follow its stitch and needle-position limits. The machine's available settings do not mean every foot permits every setting. Stop if the needle contacts a foot or plate and recheck the combination.
Needles and routine supplies
Use the needle system in the 9970 instructions, then choose the type and size for the fabric and thread. Keep installation, threading and twin-needle settings tied to the correct manual. Replace a damaged needle with a correctly matched one before testing a new accessory.
Keep references and instructions together in your accessory box. That small record helps when replacing a favourite foot or distinguishing it from a similar piece supplied with another machine.
For a particular compatibility question, contact Sewlume with Singer 9970, the proposed item reference, the intended sewing task and photographs of the current fitting.