Protective caps for Li-Po balancing connectors - JST-XH 2.5mm.
Available sizes: 2S, 3S, 4S, 5S

Additionally, more sizes can be made by editing the original STEP file (slicing in the middle and adding/subtracting 2.5mm).

Please print a single piece first and adjust scale in the slicer appropriately to account for any printer-related inaccuracies to achieve tight fit. For me, 99% scale works fine for Creality K1 with 0,4mm nozzle.