Okay, the user wants me to translate "bolt-on" into Vietnamese. Let me think about the correct translation.
First, "bolt-on" can be a noun or an adjective. As a noun, it refers to a bolt that's used to fasten things together. In Vietnamese, the direct translation for "bolt" is "đinh tán" or "bu lông". However, "bolt-on" as a term might be used in specific contexts like engineering or manufacturing.
If it's an adjective, "bolt-on" means something that's added as an extra or accessory. In that case, the translation could be "lắp thêm" or "tùy chọn". But the user provided the example translation as "bu lông", which is the noun form.
I should check if there's a standard Vietnamese term for "bolt-on" in technical contexts. Maybe "bu lông" is the most direct translation here. Since the user's example response was "bu lông", that's probably the correct choice. I'll go with that unless there's a more appropriate term, but I don't think so. So the translation is "bu lông".