Channel balance

Sure, I'm pretty certain we can help. The best replacement balance will depend greatly on the nylon caps on either end. The top one in your first picture seems to match our 19-005, but I'm not so sure about the bottom one. It could be either our 15-004 or 15-005, depending on its depth. You'll need to measure yours and refer to our dimensions to confirm the better choice.

If it's the 15-004, then I recommend our S385-29. If it's our 15-005, then I would recommend our S380-29. I would also recommend the 2840 option in either case, though you may still want to weigh your sash just in case.