Abstract: The locking device includes a first arm which may be secured to a first sliding panel such as a window. A second arm is secured to a second sliding panel which may also be a window. Each arm is secured to a major surface of the respective panel and includes a laterally extending portion which abuts an edge of the panel. Each arm also includes a depending portion, which portions are connected by a bolt which is pivotally attached at one end to one of the portions. The opposite end of the bolt is slotted to receive the other depending portion. A nut threadably engages the bolt to hold the other depending portion within the slot.