The mecgar 9mm 17rd para compatible mags have horrible baseplates. on a whim i ordered one of these, it fit the mag and most importantly with the new baseplate the mag locks into the pistol perfectly. Bought one on a whim to test and when i found that they fit and function perfectly i ordered more for all my para mags. these are a great buy for p18.9 owners that cant find original para 9mm mags. customer service is also top notch, Dawson has earned a lifetime customer.