Features:   Designed to prevent children from opening the gas   Give children a certain opening barrier with appropriate resistance settings   Parents can open buckles easily, but it is hard for children, helps preventing accidents before they can happen   Applicable for most of the gas stove knob   Assembly:   Model A,please see below photo assembly   Model B,no need remove knob,easy assmbly   have A or B can select   price is 2pcs   ​Material:plastic   more parts and toys,please vist my store: //yuanmbm.aliexpress.com/