attrib.
1- (of an extra part of machine) able to be fastened on with a bolt or catch（机器配件）可用螺栓紧固的。
1.1
- denoting something that has been or can be added to an existing object or arrangement（可以）附加的：
there's no obligation to buy any type of bolt-on insurance product with a personal loan.
没有义务用个人贷款购买任何形式的附加保险产品。
- a bolt-on part of a machine螺栓紧固配件。