I recently did the 4mm Think GPS antenna modification. I bought 11 of the antennas and used one for my PV2+ and my regular P2 I have 9 left over. The stock is a 2mm 2 dbi, where as the 4mm thick gets you 3.5 dbi. When I installed mine I placed my hand over the top of the UAV and it still held GPS antenna lock, my previous stock gps would not. I brought the UAV in the house and it still showed 11 satellites locked, then went to 8 and held those 8 until I turned off the UAV. I know some have this service for 80 to 100 bucks, but since I have these 9 to get rid of I’m offering these at ½ the cost to get rid of them. Here are the options you can have. 1. GPS update where as you send the top shell with the GPS puck still attached and after GPS upgrade is done Ill add the foil modification on the top of the shell for added security. $65 shipped inside the U.S 2. You remove the GPS puck from your top shell and just send that to me. Ill replace the 2mm GPS with the new 4mm thick and send it back. $50 Shipped inside the U.S 3. Or if you just want the 4mm Antenna and want to do the mod yourself. $12 shipped Secure Paypal is the best to protect buyer and seller, or if you have something in mind PM me and let me know. My location is WI and either of the above options would ship out the very next day after it arrives to me. If there is any interested simply pm me and we can discuss what you would like to have done. I'm just doing these 9 to get rid of them. OEM 2mm is on the left, The 4mm is the one on the right.